1. the product of all positive integers from 1 to a given number
Usage: mathematics

1. relating to a factor or factorial
Usage: mathematics

Examples

• The factorial of 5 is 120 because 5 × 4 × 3 × 2 × 1 = 120.
• We use the exclamation mark to denote factorial: 4! = 24.
• Calculating the factorial of large numbers requires careful computation.
• The factorial function grows very rapidly as numbers increase.
• In combinatorics, factorials help determine the number of permutations.
• The factorial of zero is defined as 1 by convention.