Calculate the factorial of an integer n! with trailing zeros count and mathematical expansion.
Result
Computed using 128-bit arbitrary precision BigInt math.
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n! = n × (n - 1) × ... × 2 × 1 | 0! = 1
n = 6.
6! = 720 | Trailing zeros: 1.
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Open calculatorIn combinatorics, 0! represents the number of ways to arrange an empty set, which is exactly one way. It also preserves the recursive rule n! = (n+1)! / (n+1) for n=0.
Trailing zeros are the consecutive zeros at the end of a number, produced by pairs of factors 2 and 5. Since factors of 2 are abundant, the number of trailing zeros is determined by powers of 5.
Factorials quantify permutations of discrete elements. They grow exceptionally quickly: while 10! is 3.6 million, 20! surpasses 2.4 quintillion, underpinning probability and Taylor series approximations.