24 (number)

24 (twenty-four) is the natural number following 23 and preceding 25. It is one sixth of a gross.

24 is an even composite number, a highly composite number, an abundant number, a practical number, and a congruent number.

24 is also part of the only nontrivial solution pair to the cannonball problem,^[1] and the kissing number in 4-dimensional space. An icositetragon is a regular polygon with 24 sides. A tesseract has 24 two-dimensional square faces.

• The atomic number of chromium.^[2]
• The average number of hours in a day (on Earth), also known as a mean solar day.
• 24! is an approximation (exceeding by just over 3%) of the Avogadro constant.
• 24 dm³ is the volume of one mole of any gas at room temperature and pressure.

• The number of books in the Tanakh.
• In Christian apocalyptic literature it represents the complete Church, being the sum of the 12 tribes of Israel and the 12 Apostles of the Lamb of God. For example, in The Book of Revelation: "Surrounding the throne were twenty-four other thrones, and seated on them were twenty-four elders. They were dressed in white and had crowns of gold on their heads."^[3]
• Number of Tirthankaras in Jainism.
• Number of spokes in the Ashok Chakra.

• There are a total of 24 major and minor keys in Western tonal music, not counting enharmonic equivalents. Therefore, for collections of pieces written in each key, the number of pieces in such a collection; e.g., Chopin's 24 Preludes.

• Four-and-Twenty was an American racehorse.
• In association football:
  • The FIFA World Cup final tournament featured 24 men's national teams from 1982 to 1994.
  • The FIFA Women's World Cup final tournament featured 24 national teams in 2015 and 2019.
• In basketball:
  • In the NBA, the time on a shot clock is 24 seconds.
  • One of the greatest NBA players, Kobe Bryant wore No. 24.
• In ice hockey
  • In the NHL, 24 is the record number of most Stanley Cups won in NHL history, which the Montreal Canadiens have achieved.

24 is also:

• The number of bits a computer needs to represent 24-bit color images (for a maximum of 16,777,216 colours—but greater numbers of bits provide more accurate colors).
• The number of karats representing 100% pure gold.^[4]
• The number of cycles in the Chinese solar year.
• The number of years from the start of the Cold War until the signing of the Seabed Arms Control Treaty, which banned the placing of nuclear weapons on the ocean floor within certain coastal distances.
• The number of frames per second at which motion picture film is usually projected, as this is sufficient to allow for persistence of vision.
• The number of letters in both the modern and classical Greek alphabet.^[5] For the latter reason, also the number of chapters or "books" into which Homer's Odyssey and Iliad came to be divided.
• The number of runes in the Elder Futhark.
• The number of points on a backgammon board.^[6]
• A children's mathematical game involving the use of any of the four standard operations on four numbers on a card to get 24 (see 24 Game).
• The maximum number of Knight Companions in the Order of the Garter.
• The number of the French department Dordogne.
• Four and twenty is the number of blackbirds baked in a pie in the traditional English nursery rhyme "Sing a Song of Sixpence".
• In Brazil, twenty-four is associated with homosexuality as it is the number that stands for the deer in a game known as “jogo do bicho”.

Wikimedia Commons has media related to 24 (number).

• My Favorite Numbers: 24, John C. Baez