# What is the Factorial of 20?

In this article we'll show you how to calculate the factorial of 20 with a really quick, step-by-step explanation of how it's calculated.

First off, what exactly is a factorial? The factorial is the result of multiplying all whole numbers in a chosen number (in this case 20) all the way down to 1.

You will generally see factorials expressed with an exclamation mark after the number, like so:

20!

So let's take 20 and calculate the factorial by multiplying each whole number:

20 x 19 x 18 x 17 x 16 x ... = 2432902008176640000

In this case, the number of whole numbers in 20 is more than five. You can see how this can quickly get out of hand with larger numbers.

In fact, the largest possible number you can calculate the factorial for is 170. Any higher than that, and you're looking at a mathematically infinite number!

Factorials are used in math quite a lot when calculating the number of possible combinations or permeatations of something. If you think about shuffling a deck of 52 cards, you can use factorials to calculate how many possible orders there are.

When describing a factorial you would usually say 20! like "20 factorial", "20 shriek", or "20 bang". Personally, I prefer shriek!

Hopefully this article has helped you in your quest to calculate the factorial of 20. Feel free to share with your friends, family, teachers, and anybody who might be interested in factorials of numbers (which is surely everyone!).