# 14 (number)

 ← 13 14 15 →
Cardinal fourteen
Ordinal 14th
(fourteenth)
Factorization 2 · 7
Divisors 1, 2, 7, 14
Roman numeral XIV
Greek prefix tetrakaideca-
Latin prefix quattuordec-
Binary 11102
Ternary 1123
Quaternary 324
Quinary 245
Senary 226
Octal 168
Duodecimal 1212
Vigesimal E20
Base 36 E36

14 (fourteen ) is the natural number following 13 and preceding 15.

In speech, the numbers 14 and 40 are often confused. When carefully enunciated, they differ in which syllable is stressed: 14 vs 40 .[1] When being related to the word "four" (4), 14 is spelled "fourteen", and not "forteen". However, in dates such as 1492 or when contrasting numbers in the teens, such as 13, 14, 15, the stress shifts to the first syllable: 14 .

## In mathematics

Fourteen is a composite number, its divisors being 1, 2, 7 and 14.

14 is the 3rd discrete semiprime (2.7) and the 3rd member of the (2.q) discrete semiprime family. The number following 14—15—is itself a discrete semiprime and this is the first such pair of discrete semiprimes. The next example is the pair commencing 21.

The aliquot sum σ(n) of 14 is 10, also a discrete semiprime and this is again the first example of a discrete semiprime having an aliquot sum in the same form. 14 has an aliquot sequence of 6 members (14,10,8,7,1,0) 14 is the third composite number in the 7-aliquot tree.

Fourteen is itself the Aliquot sum of two numbers; the discrete semiprime 22, and the square number 196.

Fourteen is the base of the tetradecimal notation.

In base fifteen and higher bases (such as hexadecimal), fourteen is represented as E.

Fourteen is the sum of the first three squares, which makes it a square pyramidal number.

This number is the lowest even n for which the equation φ(x) = n has no solution, making it the first even nontotient (see Euler's totient function).

14 is a Catalan number, the only semiprime among all Catalan numbers.

Take a set of real numbers and apply the closure and complement operations to it in any possible sequence. At most 14 distinct sets can be generated in this way. This holds even if the reals are replaced by a more general topological space. See Kuratowski's closure-complement problem.

Fourteen is a Keith number in base 10: 1, 4, 5, 9, 14, 23, 37, 60, 97, 157...

Fourteen is an open meandric number.

Fourteen is a Companion Pell number.

According to the Shapiro inequality 14 is the least number n such that there exist $x_1, x_2, \dots, x_n$ such that

$\sum_{i=1}^{n} \frac{x_i}{x_{i+1}+x_{i+2}} < \frac{n}{2}$

where $x_{n+1}=x_1, x_{n+2}=x_2$.

There are fourteen possible Bravais lattices that fill three-dimensional space.

The cuboctahedron, the truncated cube, and the truncated octahedron each have fourteen faces. The rhombic dodecahedron, which tessellates 3-dimensional space and is the dual of the cuboctahedron, has fourteen vertices. The truncated octahedron, which also tessellates 3-dimensional space, is the only permutohedron.

## In science

### Astronomy

• The Saros number of the solar eclipse series which began on July 31, 2568 B.C. and ended on February 6, B.C. 1035. The duration of Saros series 14 was 1532.5 years, and it contained 86 solar eclipses
• The Saros number of the lunar eclipse series which began on June 1, 2230 B.C. and ended on July 19, 932 B.C. The duration of Saros series 14 was 1298.1 years, and it contained 73 lunar eclipses.

## Age 14

• Age 14 is the earliest that the emancipation of minors can occur in the U.S.
• Minimum age a person can purchase, rent or buy tickets to a 14A rated movie in Canada without an adult. Ratings are provincial, so ratings may vary. A movie can be 14A in one or some provinces and PG in other provinces. A movie can also be rated 14A in one or some provinces and 18A in other provinces. Quebec has a different rating system for films.
• Youngest age in Canada a person can watch a 14+ rated show without consent from a legal guardian.
• Minimum age at which one can view, rent, purchase, or buy tickets to an 18A rated movie with an accompanying adult in the Canadian provinces of the Maritimes and Manitoba.
• Minimum age at which one can work in many U.S states. Some require parental consent while others don't.
• Minimum age at which one can work in most Australian states with parent's consent.
• Minimum age at which one can drive a vehicle in the U.S. with a driver's license (with supervision of an adult over 18 years of age, and with a valid, unmarked driver's license, and at least 365 days of experience driving an actual automobile)
• The minimum age limit to drive a 50cc motorbike in Italy.

## In Sports

• The G-14 is a now-defunct union of eighteen football clubs.
• In Association football: The number 14, was the number for Johan Cruyff. Therefore he is often associated with that number and the football club AFC Ajax promised (in 2007) in his honour never to use it again.
• In rugby union:
• The starting right wing wears the 14 shirt.
• The Top 14 is the highest-level league in French rugby union.
• The Southern Hemisphere competition now known as Super Rugby was known from 2006 through 2010, an era in which it had 14 teams, as Super 14.
• In the PGA:
• A player can have no more than 14 clubs in the bag.

Fourteen is:

## References

1. ^ The vowels of the syllables four- and for- are identical in many dialects, such as General American and younger speakers of Received Pronunciation.
2. ^ Jean Ann Bowman, Jorge Luis Borges: A study of criticism in the United States, M.A. thesis submitted to and approved by the Graduate Faculty of Texas Tech University, May 1987.