19 (number)

← 18 19 20 →
← 10 11 12 13 14 15 16 17 18 19 → List of numbers Integers ← 0 10 20 30 40 50 60 70 80 90 →
Cardinal	nineteen
Ordinal	th
Numeral system	nonadecimal
Factorization	prime
Divisors	1, 19
Greek numeral	ΙΘ´
Roman numeral	XIX
Binary	100112
Ternary	2013
Senary	316
Octal	238
Duodecimal	1712
Hexadecimal	1316

19 (nineteen) is the natural number following 18 and preceding 20. It is a prime number.

In speech, the numbers 19 and 90 are often confused. When carefully enunciated, they differ in which syllable is stressed: 19 /naɪnˈtiːn/ vs 90 /ˈnaɪnti/. However, in dates such as 1999, and when contrasting numbers in the teens, such as 17, 18, 19, the stress shifts to the first syllable: 19 /ˈnaɪntiːn/.

In mathematics

Nineteen is the 8th smallest prime number. The sequence continues 23, 29, 31, 37... 19 is the seventh Mersenne prime exponent. 19 is the smallest Higgs prime for squares and cubes that has an index among Higgs primes that is less than its index among primes overall (because 17 is not a Higgs prime).

Nineteen is the aliquot sum of two odd discrete biprimes, 65 and 77 and is the base of the 19-aliquot tree.

Technology

• 19 is the TCP/IP port used for chargen.

Science

• The atomic number of Potassium.

In religion

• The number of angels guarding Hell according to the Qur'an: "Over it is nineteen" (74:30)
• The number of surat Maryam in the Qur'an
• The Number of Verse and Sura together in Qur'an which describes Jesus Christ Birth (Qur'an 19:19)
• The number of Arabic letters in the common formula, the Basmala, "In the name of God, Most Gracious, Most Merciful," being (without vowel marks) "bsm allh alrḥmn alrḥym" [1]
• A number allegedly encoded in the Qur'an [2] as proposed by Dr. Rashad Khalifa, a biochemist from the USA [3] and [4]
• The Bahá'í calendar is structured such that a year contains 19 months of 19 days each (along with the intercalary period of Ayyám-i-Há), as well as a 19-year cycle and a 361-year (19x19) supercycle. The Báb and his disciples formed a group of 19, and there were 19 Apostles of Bahá'u'lláh.

In music

• 19 is the debut album from English soul and jazz singer Adele.
• 19 is the fourth studio album from Russian pop singer Alsou.
• 19 is also the title of Evan Yo's first album, because Yo was nineteen years old when the album was released.
• "19" is a 1985 hit song by Paul Hardcastle, with a strong anti-war message, including sampled soundbites taken from a documentary about the Vietnam War in which 19 is claimed to have been the average age of United States soldiers killed in the conflict (an assertion which is widely disputed). The song was parodied by British satirist Rory Bremner as N-n-nineteen, Not Out, the title referring to the English cricket team's risible performance against the West Indies in the previous year.
• With a similar name and anti-Vietnam War theme, I Was Only 19 (A Walk in the Light Green), by the Australian group Redgum reached number one on the Australian charts in 1983. In 2005 a hip hop version of the song was produced by The Herd, and was voted in at #18 in the 2005 Triple J Hottest 100 playlist.
• Other songs with the number 19 in their titles:

"Nineteen" by Bad4good

"Nineteen" by Buck-O-Nine

"Nineteen" by Phil Lynott

"Nineteen" by the Old 97's

"Hey Nineteen" by Steely Dan

"19th Nervous Breakdown" by the Rolling Stones

"Nineteen Forever" by Joe Jackson

"I Got A Feeling (Just Nineteen)" by Eagles of Death Metal

"Nineteen in Naples" by Jonathan Richman

"Nineteen" by Tegan and Sara

"Balance of the 19" by Secret Chiefs 3

"Not Nineteen Forever" by The Courteeners

"I Was Only Nineteen" by Redgum

• Nineteen has been used as an alternative to twelve for a division of the octave into equal parts. This idea goes back to Salinas in the sixteenth century, and is interesting in part because it gives a system of meantone tuning, being close to 1/3 comma meantone.

• Some organs use the 19th harmonic to approximate a minor third.

• It also may refer to 19 Entertainment, an entertainment agency.

Literature

• Stephen King's seven book epic The Dark Tower saga employs the number 19 in books The Dark Tower: The Gunslinger, The Dark Tower V: Wolves of the Calla, The Dark Tower VI: Song of Susannah, and The Dark Tower as a mysterious and important number. They refer to the "ka-tet of 19, many names add up to 19, 19 seems to permeate every aspect of Roland and his traveler's lives. In addition, the number ends up being a powerful key.

• In Harry Potter and the Deathly Hallows the epilogue starts 19 years after the end of the actual story.

• In Jodi Picoult's best seller book Nineteen Minutes, the number 19 is referenced multiple times. It is most commonly referenced when referring to the main subject of the book, the school shooting rampage that took place over a span of 19 minutes.

In Games

19 is the command in Age of Empires for the laughing emote. This was an easier way to laugh before "LOL" existed.

Though the maximum score for a hand of cribbage is 29, there is no known combination of cards that adds up to 19 points. Many cribbage players, therefore, jokingly refer to a zero-point hand as "19 points."

Age 19

• This is the minimum age that is legal to buy tobacco products in Alabama, Alaska, New Jersey, Texas, Utah, and Nassau, Suffolk, and Onondaga counties in New York).

In other fields

Nineteen is:

• The nineteenth President of the United States was Rutherford B. Hayes.
• The nineteenth state to enter the Union of the United States was Indiana
• Part of the name of a breakfast cereal: Product 19
• The Soviet submarine K-19 was the first Soviet nuclear ballistic submarine
• I-19 is the designation for a US interstate highway in Arizona
• the height, in feet, of the statues of Abraham Lincoln and Thomas Jefferson in their respective memorials.
• 19 years is very close to 235 lunations. See Metonic cycle
• In golf the "19th hole" is the clubhouse bar. In miniature golf it is an extra hole on which the winner earns an instant prize
• A number encoded in Chemistry as claimed by Dr. Peter Plichta, a German chemist [5]. Also see [6] for Plichta's claimed code-19 in chemistry
• In the National Hockey League, Joe Sakic of the Colorado avalanche wore number 19.
• The retired football jersey number of Hall of Famers Johnny Unitas and Lance Alworth
• The retired baseball jersey number of Baseball Hall of Fame members Robin Yount,Tony Gwynn, and Bob Feller.
• The retired basketball jersey number of Willis Reed.
• The retired Detroit Red Wings hockey jersey number of Steve Yzerman.
• The retired Minnesota North Stars hockey jersey number of Bill Masterton.
• The retired Montreal Canadiens hockey jersey number of Larry Robinson.
• The retired New York Islanders hockey jersey number of Brian Trottier.
• 19 x 19 is also the standard size of a Go Board
• The number of the French department Corrèze

Historical years

A.D. 19, 19 B.C., 1919, 2019, etc.

External links

• 19.ORG
• Prime Curios for the number 19
• Agir XIX