24

24 (twenty-four) is a positive integer following 23 and preceding 25.
== Properties ==
*24 is an OEIS, sequence A002808 (accessed 2020-11-13) and the fourth factorial number.
*There are 24 hours in a day.
*The 24th of December is known around the world as Christmas Eve.
*24 is the largest number divisible by all integers less than its square root.
*It is the smallest positive integer whose square contains the digit 7.
*It is the 3rd smallest number that is known to be . Its smallest friend is 91963648.
*It is the smallest non-unitary perfect number.
== In googology ==
*In Greek-based number-naming systems, 24 is associated with prefix "tetraicosa-", and with prefix "quattuorviginti-" in Latin systems. In the Misalian seximal system, this number is called "foursy", because it's six times four.
*Furthermore, it is the largest number n with the following property: Let f: ℕ → ℕ, f(a) = aa. Then for every a ∈ ℕ, there is a b ∈ ℕ, such that fb+1(a) ≡ fb(a) (mod n).
*HaydenTheGoogologist2009 coined Yummy! for this number, and it's the 3rd number in Meet yourself in 105 degrees Celsius.Hayden's Big Numbers - Meet yourself in 105 degrees Celsius. Retrieved 2023-03-18.
=== Googological functions returning 24 ===
*Factorial: 4! = 24
*Torian: \(T(3)=24\)
* Bouncing factorial: \(3\Lambda = 24\)
==See also==
*Septillion, 1024 using the short scale
*Factorial
==Sources==
Category:Numbers
Category:Numbers 0-99
Category:Class 1
Category:Factorial numbers
Category:Numbers with 1 to 2 digits
Category:Orders of symmetric groups