❗ ফ্যাক্টর ক্যালকুলেটর

এই ক্যালকুলেটর সম্পর্কে

The factorial of n (written n!) is the product of every whole number from 1 up to n. This calculator returns the exact value using arbitrary-precision integers, the number of digits in that value, and an approximate mantissa × power-of-ten form for readability.

The calculation is a running product: 5! = 5 × 4 × 3 × 2 × 1 = 120. Factorials grow extremely fast — 10! = 3,628,800 and 100! already has 158 digits — which is why the tool shows both the full exact integer and its digit count. By definition 0! = 1 and 1! = 1, since there is exactly one way to arrange an empty or single-item set. It accepts n from 0 up to 2000.

Factorials count the number of ways to order n distinct items and are the foundation of permutations and combinations, the binomial theorem, and probability. Whenever you count arrangements or divide out orderings, a factorial is doing the work underneath.