# 13 (number)

 ← 12 13 14 →
Cardinal thirteen
Ordinal 13th
(thirteenth)
Factorization prime
Prime 6th
Divisors 1, 13
Roman numeral XIII
Binary 11012
Ternary 1113
Quaternary 314
Octal 158
Duodecimal 1112
Vigesimal D20
Base 36 D36

13 (thirteen ) is a natural number after 12 and before 14. It is the smallest number with eight letters in its name spelled out in English.

In speech, the numbers 13 and 30 are often confused. When carefully enunciated, they differ in which syllable is stressed: 13 vs. 30 . However, in dates such as 1300 ("thirteen hundred") or when contrasting numbers in the teens, such as 13, 14, 15, the stress shifts to the first syllable: 13 .

Strikingly similar folkloric aspects of the number 13 have been noted in various cultures around the world: one theory is that this is due to the cultures employing lunar-solar calendars (there are approximately 12.41 lunations per solar year, and hence 12 "true months" plus a smaller, and often portentous, thirteenth month). This can be witnessed, for example, in the "Twelve Days of Christmas" of Western European tradition.[1]

## In mathematics

The number 13 is the sixth prime number, and the smallest emirp (prime which is a different prime when reversed).[2] It is also a Fibonacci number, a happy number, and one of only 3 known Wilson primes.

Since 52 + 122 = 132, (5, 12, 13) forms a Pythagorean triple.

There are 13 Archimedean solids, and a standard torus can be sliced into 13 pieces with just 3 plane cuts.[2] There are also 13 different ways for the three fastest horses in a horse race to finish, allowing for ties, a fact that can be expressed mathematically by 13 being the third ordered Bell number.[3]

### List of basic calculations

Multiplication 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 50 100 1000
$13 \times x$ 13 26 39 52 65 78 91 104 117 130 143 156 169 182 195 208 221 234 247 260 273 286 299 312 325 650 1300 13000
Exponentiation 1 2 3 4 5 6 7 8 9 10 11 12 13
$13 ^ x\,$ 13 169 2197 28561 371293 4826809 62748517 815730721 10604499373 137858491849 1792160394037 23298085122481 302875106592253
$x ^ {13}\,$ 1 8192 1594323 67108864 1220703125 13060694016 96889010407 549755813888 2541865828329 10000000000000 34522712143931 106993205379072 302875106592253

## In languages

### Grammar

• In all Germanic languages (such as English and German), 13 is the first compound number; the numbers 11 and 12 have their own names (in German elf and zwölf).
• The Romance languages use different systems: In Italian, 11 is the first compound number (ùndici), while in Spanish und Portuguese, the numbers up to and including 15 (Spanish quince, Portuguese quinze), in French up to and including 16 (seize) have their own names.
• Like in Italian, in many other languages, 11 is the first compound number, e.g. in Arabic, Chinese, Hungarian, Japanese, Swahili.
• In Lithuanian and Slavic languages, the numbers from 11-19 have their own names.
• In Hindi-Urdu, nearly every number from 1–99 is irregular and needs to be memorized as a separate numeral.

### Spelling

In Germany, according to an old rule, 13 as the first compound number was the first number to be written in digits; the numbers 0 through 12 were to be spelled out. The Duden (the German standard dictionary) now calls this rule outdated and no longer valid, but many writers still follow it.

For the English language, different systems are used: Sometimes it is recommended to spell out numbers up to and including nine or ten or even ninety-nine or one hundred. Another system spells out all numbers written in one or two words (fifteen thousand, but 15,001).

## In religion

### Roman Catholicism

The apparitions of the Virgin of Fátima in 1917 were claimed to occur on the 13th day of six consecutive months.[4]

In Catholic devotional practice, the number thirteen is also associated with Saint Anthony of Padua, since his feast day falls on June 13. A traditional devotion called the Thirteen Tuesdays of St. Anthony [5] involves praying to the saint every Tuesday over a period of thirteen weeks. Another devotion, St. Anthony's Chaplet,[6] consists of thirteen decades of three beads each.

### Sikhism

According to famous Sakhi (Evidence) or story of Guru Nanak Dev Ji, when he was an accountant at a town of Sultanpur Lodhi, he was distributing grocery to people and when he gave groceries to the 13th person he stopped there because in Gurmukhi and Hindi the word 13 is called Terah, which means yours. And Guru Nanak Dev Ji kept on saying, "Yours, yours, yours..." remembering God. People reported to the emperor that Guru Nanak Dev Ji was giving out free food to the people. When treasures were checked, there was more money than before.

The Vaisakhi which commemorates the creation of "Khalsa" or pure Sikh was celebrated on April 13 for many years.

### Zoroastrianism

Evidently the number 13 had been considered sinister and wicked in ancient Iranian civilization and Zoroastrianism; Since beginning of Nourooz tradition, the 13th day of each new Iranian year is called Sizdah Be-dar and this tradition is still alive among Iranian people both inside modern Iran and abroad. Since Sizdah Be-dar is the 13th day of the year, it is considered a day which evil's power might cause difficulties for people; Therefore people desert the cities and urban areas for one day and camp in the countryside. Even in the current era after 1979 Revolution and despite the wishes of Islamic government this day is officially holiday all over Iran and its traditions are practiced by the majority of people.

### Islam

In Shia Islam 13 signifies the 13th day of the month of Rajab (Lunar calendar) which is the birth of Imam Ali. 13 also is a total of 1 Prophet and 12 Imams in the Shia school of thought.

### Other

• In Mesoamerican divination, 13 is the number of important cycles of fortune/misfortune (see Trecena).[citation needed]
• 13 is the age that adepts usually start to learn Witchcraft.[dubious ]
• Traditionally, there are 13 witches in a coven.[citation needed]
• In a Pentagram with a circle ratio of 13, each arm of the star will equal 12.36, the number of lunar months,days and hours in a solar year. Add the arms together and you get the number of full moons in 5 years.[citation needed]
• Many religions have 1 Messiah or Prophet and 12 followers for a total of 13.[citation needed]

## Lucky and unlucky

### Unlucky 13

The number 13 is considered an unlucky number in some countries.[7] Charles Stewart Parnell had an irrational fear of the number thirteen [8] The end of the Mayan calendar's 13th Baktun was superstitiously feared as a harbinger of the apocalyptic 2012 phenomenon.[9] Fear of the number 13 has a specifically recognized phobia, Triskaidekaphobia, a word which was coined in 1911. The superstitious sufferers of triskaidekaphobia try to avoid bad luck by keeping away from anything numbered or labelled thirteen. As a result, companies and manufacturers use another way of numbering or labeling to avoid the number, with hotels and tall buildings being conspicuous examples (Thirteenth floor).[10] It's also considered to be unlucky to have thirteen guests at a table. Friday the 13th has been considered the unluckiest day of the month. [7]

There are a number of theories behind the cause of the association between thirteen and bad luck, but none of them have been accepted as likely.[7]

#### The Last Supper

At Jesus Christ's last supper, there were thirteen people around the table, counting Christ and the twelve apostles. The reason this is believed to be unlucky is because one of those thirteen, Judas Iscariot, was the betrayer of Jesus Christ.

#### Knights Templar

On Friday 13 October 1307, King Philip IV of France ordered the arrest of the Knights Templar.[7]

#### Full moons

A year which contained 13 full moons instead of 12 posed problems for the monks who were in charge of the calendars. "This was considered a very unfortunate circumstance, especially by the monks who had charge of the calendar of thirteen months for that year, and it upset the regular arrangement of church festivals. For this reason thirteen came to be considered an unlucky number."[11]

However, in a typical century, there will be about 37 years which have 13 full moons compared with 63 years with 12 full moons, and typically every third or fourth year would have 13 full moons.[12]

The moon moves 13 degrees around the earth every day. It Takes 13 days to change from Full Moon to New Moon and 13 days to change back with 1 day Full and 1 day New to equal 28 days of the Lunar Cycle.

#### A repressed lunar cult

In ancient cultures, the number 13 represented femininity, because it corresponded to the number of lunar (menstrual) cycles in a year (13 x 28 = 364 days). The theory is that, as the solar calendar triumphed over the lunar, the number thirteen became anathema.[7][13]

### Lucky 13

Several successful sports figures have worn the number 13. Park Ji-Sung, South-Korean footballer and midfielder for Queens Park Rangers wears number 13. Ozzie Guillén, manager of the 2005 World Series Champion Chicago White Sox, has worn the number throughout his baseball career. Alex Rodriguez began wearing it upon joining the New York Yankees (three, the number he had previously worn, is retired by the Bronx Bombers to honor Babe Ruth). Dan Marino, an American football player known for passing the 3rd most yards in NFL history, wore the number 13. Basketball great Wilt Chamberlain wore the number 13 on his jersey throughout his NBA career. Also, FIBA rules require a player to wear the number in international competitions (only numbers from 4 to 15 could be worn, and as there are 12 players, one must wear 13); Chris Mullin, who wore No. 20 in college and No. 17 in the NBA, wore No. 13 for both (1984 and 1992) of his Olympic appearances. Shaquille O'Neal wore No. 13 in 1996; Tim Duncan wore No. 13 in 2004. Steve Nash wore it for most of his basketball career. Yao Ming wore it in the 2008 Olympics in Beijing. Chris Paul wore the number 13 for both the 2008 and 2012 Olympics. Mats Sundin, Pavel Datsyuk, Bill Guerin, and Michael Cammalleri wear 13 in the NHL. One of Iceland's all time best handball players, Sigurður Sveinsson, wore the number 13 when he played for the national team. In association football, both Gerd Müller and Michael Ballack have favoured the number 13, among others.

In Italy, 13 is also considered to be a lucky number, although in Campania the expression 'tredici' (meaning 13) is said when one considers their luck to have turned for the worse.

Some people even have 13 tattooed onto them to represent the lucky number.

### Music

American born Horror-Punk singer and musician Joseph Poole (Murderdolls) uses the name Wednesday 13 as his stage name, taking "Wednesday" from the girl Wednesday from the Addams Family and 13 from Friday the 13th.

American country-pop singer-songwriter Taylor Swift was born on December 13. She considers 13 her lucky number due to lucky events happening to her when the number appears (her first album going gold in 13 weeks, being seated at awards shows in the 13th seat, row or section). She also wears the number written on her hand at her concerts so she has it with her everywhere she goes.

The heavy metal band, Megadeth, released their 13th studio album entitled TH1RT3EN on November 1, 2011. It consists of 13 tracks including the final song "13".

Famous American country singer and songwriter Johnny Cash first released his song called "Number Thirteen".

There are 13 notes, by inclusive counting, in a full chromatic musical octave.

The Band Big Star Wrote a song called 13

The Band Teenage Fanclub Named their album Thirteen after Big Star's song. The band were heavily influenced by Big Star.

American alternative rock band, Pixies recorded "Number 13 Baby" for their Doolittle LP. The lyrics to the song include the line: "Standing in her chinos shirt pulled off clean, gotta tattooed tit say number 13"

English alternative rock band Blur's sixth studio album, entitled 13 was released in 1999.

### Other

Colgate University also considers 13 to be a lucky number. They were founded in 1819 by 13 men with 13 dollars, 13 prayers and 13 articles.[14] (To this day, members of the Colgate community consider the number 13 a good omen.) In fact, the campus address is 13 Oak Drive in Hamilton, New York, and the male a cappella group is called the Colgate 13.

In the Mayan Tzolk'in calendar, trecenas mark cycles of 13 day periods. The pyramids are also set up in 9 steps divided into 7 days and 6 nights, 13 days total.

In a tarot card deck, XIII is the card of Death, usually picturing the Pale horse with its rider.

#### Coperos

The number 13 in the Coperos religion (small culture in Brazil) is like a God number. All coperos must know that this number can save humankind.

#### History

The American flag has 13 stripes in honor of the first 13 colonies.

Apollo 13 was a NASA Moon mission famous for being a "successful failure" in that while the crew were unable to land on the Moon as planned due to a technical malfunction, they were returned safely home.

## Age 13

• In Judaism, 13 signifies the age at which a boy matures and becomes a Bar Mitzvah, i.e., a full member of the Jewish faith (is qualified to be counted as a member of Minyan).

## In sports

In rugby league:

• Each side has 13 players on the field at any given time.
• The jersey number 13 is worn by the starting loose forward or lock forward in most competitions. An exception is in the European Super League, which uses static squad numbering.

The jersey number 13 has been retired by several North American sports teams, usually in honor of past playing greats:

In Formula One and triathlon, the number 13 is not used. As such, the numbering goes 11, 12, 14, 15 under the current numbering system.

In U.S. college athletics, schools that are members of NCAA Division I are allowed to provide athletic scholarships to a maximum of 13 men's basketball players in a given season.

In rugby union, the jersey number 13 is worn by one of the two starting centres, usually the outside centre but sometimes the inside centre.

The number 13 is the most-commonly registered jersey number in modern roller derby.[15]

## References

1. ^ Frazier, King of the Bean, and the Festival of Fools. Cited in Thompson, Tok. 2002. The thirteenth number: Then, there/ here and now. 'Studia Mythological Slavica 5, 145–159.
2. ^ a b Wells, D. The Penguin Dictionary of Curious and Interesting Numbers, London: Penguin Group. (1987): 67–71.
3. ^ de Koninck, J. M. (2009), Those Fascinating Numbers, American Mathematical Society, p. 4, ISBN 9780821886311.
4. ^ Rosemary Guiley, The Guinness Encyclopedia of Ghosts and Spirits, 1994, p. 215, ISBN 0-85112-748-7.
5. ^ http://www.shrineofstanthony.org
6. ^ http://www.catholicculture.org/culture