# factorial

fac·to·ri·al- of a factor
- Math. of factors or factorials

Math. the product of a given series of consecutive whole numbers beginning with 1 and ending with the specified number: the

*factorial*of 5 (5!) is 1 × 2 × 3 × 4 × 5, or 120## factorial

noun

The product of all the positive integers from 1 to a given number:

*4 factorial, usually written 4!, is equal to 24 (1 × 2 × 3 × 4 = 24).*adjective

Of or relating to a factor or factorial.

## factorial

Noun

(*plural* factorials)

- (mathematics, combinatorics) The result of multiplying a given number of consecutive integers from 1 to the given number. In equations, it is symbolized by an exclamation mark (!). For example, 5! = 1 * 2 * 3 * 4 * 5 = 120.

Usage notes

"*n*!" is read as "factorial of *n*" or "*n* factorial."