# What is 99 factorial ?

Steps to calculate factorial of 99

## How to calculate the factorial of 99

To find 99 factorial, or 99!, simply use the formula that multiplies the number 99 by all positive whole numbers less than it.

Let's look at how to calculate the Factorial of Ninety-nine :

99! is exactly : 933262154439441526816992388562667004907159682643816214685929638952175999932299156089414639761565182862536979208272237582511852109168640000000000000000000000

Factorial of 99 can be calculated as:
99! = 99 x 98 x 97 x 96 x ... x 3 x 2 x 1

The number of trailing zeros in 99! is 23

The number of digits in 99 factorial is 156.

## What Is Factorial?

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

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

Symbolically, it is displayed as "!".

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

## Factorial Formula

To find the factorial of any given number, alternate the exact value for n in the given method :

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

The expansion of the formula provides the numbers to be replicated with each other 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 :
99! Factorial = 99 x 98 x 97 x 96 x ... x 3 x 2 x 1 = 99 × 98! = 933262154439441526816992388562667004907159682643816214685929638952175999932299156089414639761565182862536979208272237582511852109168640000000000000000000000

## 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 value is corresponding to 1. So, 0! = 1.