## How to calculate the factorial of **100**

To find 100 factorial, or **100!**,
simply use the formula that multiplies the number 100 by all positive whole numbers less than it.

Let's look at how to calculate the Factorial of
**One hundred ** :

**100!** is exactly : **93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000**

Factorial of **100** can be calculated as:

**100!** = **100 x 99 x 98 x 97 x ... x 3 x 2 x 1**

The number of trailing zeros in
**100!** is **24**

The number of digits in **100** factorial is **158**.

## Factorials of Numbers similar to **100**

## What Is Factorial?

A factorial is showed by an integer and an exclamation tag. In arithmetic, factorial is a multiplication process of natural numbers .

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

Symbolically, it is showed as "!".

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

## Factorial Formula

To find the factorial of any given number, replace 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 provides numbers to be multiplied together to receive the factorial of the number.

We can also calculate a factorial from the prior 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 :

**100!** Factorial =
100 x 99 x 98 x 97 x ... x 3 x 2 x 1 =
100 × 99! =
93326215443944152681699238856266700490715968264381621468592963895217599993229915608941463976156518286253697920827223758251185210916864000000000000000000000000

## 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

### Can we have factorials for negative numbers ?

Negative integer factorials are undefined

### What Is 0!

Zero factorial or Factorial of 0 is simple, and its own value is equal to 1. So, 0! = 1.