Online calculator computes Stirling's approximation of factorial of given positive integer (up to 170!)

This calculator calculates the number of combinations, arrangements and permutations for given n and m

This combinations calculator generates all possible combinations of m elements from the set of n elements.

This calculator generates all pairs of factors for given integer.

Combinatorics. Permutation generator from N to M with repetitions.

Combinatorics. Permutation generator from n to m without repetitions

Calculation of the Gamma function using Lanczos approximation

For elements with weights this calculator can filter out all combinations where total weight is under the specified limit.

This online calculator calculates factorial of a positive integer. Practically unlimited positive integer. In fact, it is limited only by the time you are willing to wait until calculation completes. I was patient enough to wait for 100000!

This article describes how to perform long or infinite calculations while allowing user to stop them

This online calculator solves factorial division problems when you have factorials in the numerator and denominator.