# What is 31 factorial ?

Steps to calculate factorial of 31

## How to calculate the factorial of 31

To find 31 factorial, or 31!, simply use the formula that multiplies the number 31 by all positive whole numbers less than it.

Let's look at how to calculate the Factorial of Thirty-one :

31! is exactly : 8222838654177922817725562880000000

Factorial of 31 can be calculated as:
31! = 31 x 30 x 29 x 28 x ... x 3 x 2 x 1

The number of trailing zeros in 31! is 7

The number of digits in 31 factorial is 34.

## What Is Factorial?

A factorial is showed by an integer and an exclamation symbol. In Mathematics, factorial is a multiplication function of natural numbers .

It multiplies the number by every natural number that is less than it .

Symbolically, it is represented as "!".

The function is used, among other things, to find the "n" way elements can be structured .

## Factorial Formula

To find the factorial of any given number, exchange the exact value for n in the given formula :

n! = n × (n-1) × (n-2) × (n-3) × ….× 3 × 2 × 1

The expansion of the formula shows the numbers to be replicated at the same time to find the factorial of the number.

We can also measure a factorial from the previous one. The factorial of any number is that number replicated the factorial of (that number minus 1).

So the rule is : n! = n × (n−1)!

Example :
31! Factorial = 31 x 30 x 29 x 28 x ... x 3 x 2 x 1 = 31 × 30! = 8222838654177922817725562880000000

## What are Factorials Used For?

The best use of factorial is in Combinations and Permutations.

Example : Determine how to arrange letters without repeating?

There one way for 1 letter "a":
2 ways for two letters "ab": ab, ba.
There are 6 ways for 3 letters "abc": abc acb cab bac bca.
There are 24 ways for 1234 of the letters "abcd"

## Frequently Asked Questions on Factorial

1) Can we have factorials for negative numbers ?
Negative number factorials are undefined

2) What Is 0!
Zero factorial or Factorial of 0 is simple, and its own value is corresponding to 1. So, 0! = 1.