Factorial Calculator
Factorial (n!)
Calculate n! = n × (n-1) × ... × 2 × 1
Formula
n! = n × (n-1) × (n-2) × ... × 2 × 1 | 0! = 1
Frequently Asked Questions
What is a factorial?
n! (n factorial) is the product of all positive integers up to n. 5! = 5×4×3×2×1 = 120. By convention, 0! = 1.
Where are factorials used?
Factorials appear in permutations (nPr = n!/(n-r)!), combinations (nCr = n!/(r!(n-r)!)), probability, Taylor series, and many areas of mathematics.
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