Calculate n! (n factorial) for any non-negative integer, instantly.
The factorial of a number n (written n!) is the product of every positive integer from 1 up to n. Factorials show up constantly in probability, combinatorics, and statistics.
n! = n × (n-1) × (n-2) × ... × 2 × 1, with 0! defined as 1.
7! = 7 × 6 × 5 × 4 × 3 × 2 × 1 = 5,040.
The factorial of a number n (written n!) is the product of all positive integers from 1 up to n — for example, 5! = 5×4×3×2×1 = 120.
0! is defined as 1, a mathematical convention that makes many combinatorics formulas work consistently.
They're fundamental in combinatorics for counting permutations and combinations, and appear throughout probability, statistics, and calculus (like in Taylor series).