# What is 4! - Factorial for integer 4?

## Definition and Formula

**Factorial** is a basic mathematic function often represented by **n!** in mathematics, represents the product of all integers less than or equal to the positive integer n. An important function frequently used in combinatorics (*permutations* and *combinations*) theory.

For example, 4! can be written as

4! = 1 x 2 x 3 x 4

4! = 24