AbraCalc

What is 100! (100 Factorial)?

100 factorial is an astronomically large number with 158 digits, far exceeding the number of atoms in the observable universe.

Embed this tool on your site

How to use this tool

  1. Enter n in the fields above.
  2. Results update instantly as you type — or click Calculate.
  3. Read your n! and the full breakdown beneath it.

100! is a famous large number in mathematics — it has 158 digits and is used in many combinatorics proofs.

Frequently asked questions

What is a factorial?
The factorial of n (written n!) is the product of all positive integers up to n. By definition, 0! = 1.