About Factorials

The factorial of a non-negative integer \( n \) is the product of all positive integers less than or equal to \( n \). This calculator computes it using the formula:

• \( n! = n \times (n-1) \times (n-2) \times \cdots \times 1 \)
• \( 0! = 1 \) (by definition)

For example, \( 5! = 5 \times 4 \times 3 \times 2 \times 1 = 120 \).