# Factorial _Read this in other languages:_ [_简体中文_](README.zh-CN.md), [_Français_](README.fr-FR.md), [_Türkçe_](README.tr-TR.md), [_ქართული_](README.ka-GE.md), [_Українська_](README.uk-UA.md). In mathematics, the factorial of a non-negative integer `n`, denoted by `n!`, is the product of all positive integers less than or equal to `n`. For example: ``` 5! = 5 * 4 * 3 * 2 * 1 = 120 ``` | n | n! | | --- | ----------------: | | 0 | 1 | | 1 | 1 | | 2 | 2 | | 3 | 6 | | 4 | 24 | | 5 | 120 | | 6 | 720 | | 7 | 5 040 | | 8 | 40 320 | | 9 | 362 880 | | 10 | 3 628 800 | | 11 | 39 916 800 | | 12 | 479 001 600 | | 13 | 6 227 020 800 | | 14 | 87 178 291 200 | | 15 | 1 307 674 368 000 | ## References [Wikipedia](https://en.wikipedia.org/wiki/Factorial)