# What is 100 factorial ?

Steps to calculate factorial of 100

## 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.

## What Is Factorial?

A factorial is represented by an integer and an exclamation symbol. In math concepts, factorial is a multiplication treatment of natural numbers .

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

Symbolically, it is symbolized as "!".

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

## Factorial Formula

To find the factorial of any given number, substitute the exact value for n in the given equation :

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

The expansion of the formula provides the numbers to be multiplied at the same time to obtain the factorial of the number.

We can also calculate a factorial from the prior one. The factorial of any number is that number multiplied 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 number factorials are undefined

### What Is 0!

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