What is 20! (20 Factorial)?
20! (20 factorial) equals 2,432,902,008,176,640,000.
How to use this tool
- Enter n in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your n! and the full breakdown beneath it.
20 factorial is a very large number — 2,432,902,008,176,640,000 — calculate it here.
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.