# 22 (number)

This article may contain indiscriminate, excessive, or irrelevant examples. (March 2010) |

**22** (**twenty-two**) is the natural number following 21 and preceding 23.

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Cardinal | twenty-two | |||

Ordinal | 22nd (twenty-second) | |||

Factorization | 2 × 11 | |||

Divisors | 1, 2, 11, 22 | |||

Greek numeral | ΚΒ´ | |||

Roman numeral | XXII | |||

Binary | 10110_{2} | |||

Ternary | 211_{3} | |||

Quaternary | 112_{4} | |||

Quinary | 42_{5} | |||

Senary | 34_{6} | |||

Octal | 26_{8} | |||

Duodecimal | 1A_{12} | |||

Hexadecimal | 16_{16} | |||

Vigesimal | 12_{20} | |||

Base 36 | M_{36} |

## Contents

## In mathematicsEdit

- 22 is a deficient number.
- 22 is an even composite number and a semiprime; its proper divisors are 1, 2, and 11.
- 22 is a pentagonal number
^{[1]}and a centered heptagonal number.^{[2]} - When cutting a circle with just six line segments, the maximum number of pieces that can be so created is 22,
^{[3]}thus 22 is a central polygonal number (see lazy caterer's sequence).^{[4]} - 22 is the number of partitions of 8.
- 22 is the sum of the totient function for the first eight integers.
^{[5]} - 22 is a Perrin number, preceded in the sequence by 10, 12, and 17.
^{[6]} - 22 divided by 7 approximates the irrational number π, the ratio of the circumference of a circle to its diameter.
- 22 is an Erdős–Woods number, since it is possible to find sequences of 22 consecutive integers such that each inner member shares a factor with either the first or the last member.
^{[7]} - 22 is a Smith number in base 10.
^{[8]} - "2-2" is the only fixed point of John Conway's look-and-say function.
^{[9]}^{[importance?]}

## In physics and chemistryEdit

- 22 is the atomic number of titanium.

## In aircraftEdit

- 22 is the designation of the USAF stealth fighter, the F-22 Raptor.

## In art, entertainment, and mediaEdit

### In musicEdit

- "Twenty Two" is a 1997 song by the punk band Millencolin
- In Jay-Z's song "22 Two's", he rhymes the words: too, to, and two, 22 times in the first verse.
- "22 Acacia Avenue" is a song by Iron Maiden on the album
*The Number of the Beast* *Catch 22*is an album by death metal band Hypocrisy- "22" is a song by Lily Allen on the album
*It's Not Me, It's You*. *22 Dreams*is a song and album by Paul Weller. The album contains 22 songs on it.- The Norwegian electronica project Ugress uses 22 as a recurring theme. All four albums feature a track with 22 in the title.
- "22" is a song by Taylor Swift on her fourth album
*Red* - "The Number 22" is a song by Ashbury Heights on the album
*The Looking Glass Society*. *22, A Million*is an album by Bon Iver. The first track of the album is called "22 (OVER SOON)".- Cubic 22 was a Belgian techno duo.
- "22" is a song by the English alternative rock band Deaf Havana on their album Old Souls
- "22" is a song by the Irish singer Sarah McTernan. She will represent Ireland with this song in Eurovision 2019.

### In other fieldsEdit

*Catch-22*(1961), Joseph Heller's novel, and its 1970 film adaptation gave rise to the expression of logic "catch-22".*Revista 22*is a magazine published in Romania.- There are 22 stars in the Paramount Pictures logo.
- "Twenty Two" (February 10, 1961) is Season 2–episode 17 (February 10, 1961) of the 1959-64 TV series
*The Twilight Zone*, in which a hospitalized dancer has nightmares about a sinister nurse inviting her to Room 22, the hospital morgue. - Traditional Tarot decks have 22 cards with allegorical subjects. These serve as trump cards in the game. The Fool is usually a kind of wild-card among the trumps and unnumbered, so the highest trump is numbered 21. Occult Tarot decks usually have 22 similar cards which are called Major Arcana by fortune-tellers. Occultists have related this number to the 22 letters of the Hebrew alphabet and the 22 paths in the Kabbalistic Tree of Life.

## In computing and technologyEdit

- 22 is the standard port number for the Secure Shell protocol
- A quotation mark (in a URL it appears as a "%22")

## In religionEdit

- There are 22 letters in the Hebrew alphabet.
- In the Kabbalah, there are 22 paths between the
*Sephirot*.

## In sportsEdit

- In both American football and association football, a total of 22 players (counting both teams) start the game, and this is also the maximum number of players that can be legally involved in play at any given time.
- In Australian rules football, each team is allowed a squad of 22 players (18 on the field and 4 interchanges).
- The length of a cricket pitch is 22 yards.
- In rugby union, the "22" is a line in each half of the field which is 22 meters from the respective try line. It has significance in a number of laws particularly relating to kicking the ball away.
- A snooker game (called a "frame") starts with 22 coloured balls at specified locations on the table (15 red balls and 7 others).

## In weights and measuresEdit

## In other usesEdit

**Twenty-two** may also refer to:

- 22 is the number of the French department Côtes-d'Armor
- "22" is a common name for the .22 calibre .22 Long Rifle cartridge.
- In French jargon, "22" is used as a phrase to warn of the coming of the police (typically
*"22, v'là les flics !"*(In English: "5-0! Cops!") - In photography, f/22 is the largest f-stop (and thus smallest aperture) available on most lenses made for single-lens reflex cameras
- The total number of cases on
*Deal or No Deal*

## See alsoEdit

- Catch 22 (disambiguation)
- List of highways numbered 22
- Synchronicity
^{[relevant? – discuss]}

## ReferencesEdit

**^**Sloane, N. J. A. (ed.). "Sequence A000326 (Pentagonal numbers)".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-05-31.**^**Sloane, N. J. A. (ed.). "Sequence A069099 (Centered heptagonal numbers)".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-05-31.**^**Wells, D.*The Penguin Dictionary of Curious and Interesting Numbers*London: Penguin Group. (1986): 31**^**Sloane, N. J. A. (ed.). "Sequence A000124 (Central polygonal numbers (the Lazy Caterer's sequence))".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-05-31.**^**Sloane, N. J. A. (ed.). "Sequence A002088 (Sum of totient function)".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-05-31.**^**Sloane, N. J. A. (ed.). "Sequence A001608 (Perrin sequence)".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-05-31.**^**Sloane, N. J. A. (ed.). "Sequence A059756 (Erdős-Woods numbers)".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-05-31.**^**Sloane, N. J. A. (ed.). "Sequence A006753 (Smith numbers)".*The On-Line Encyclopedia of Integer Sequences*. OEIS Foundation. Retrieved 2016-05-31.**^**Martin, Oscar (2006). "Look-and-Say Biochemistry: Exponential RNA and Multistranded DNA" (PDF).*American Mathematical Monthly*. Mathematical association of America.**113**(4): 289–307. doi:10.2307/27641915. ISSN 0002-9890. Archived from the original (PDF) on 2006-12-24. Retrieved 2018-11-21.

## External linksEdit

Wikimedia Commons has media related to .22 (number) |

- "The Number 22 at The Database of Number Correlations".
*Virtuescience*.