# What is 9 factorial ?

Steps to calculate factorial of 9

## How to calculate the factorial of 9

To find 9 factorial, or 9!, simply use the formula that multiplies the number 9 by all positive whole numbers less than it.

Let's look at how to calculate the Factorial of Nine :

9! is exactly : 362880

Factorial of 9 can be calculated as:
9! = 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1

The number of trailing zeros in 9! is 1

The number of digits in 9 factorial is 6.

## What Is Factorial?

A factorial is represented by an integer and an exclamation mark. In arithmetic, factorial is a multiplication procedure of natural numbers .

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

Symbolically, it is showed as "!".

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

## Factorial Formula

To find the factorial of any given number, replace the exact value for n in the given solution :

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

The expansion of the formula shows the numbers to be multiplied to each other to get the factorial of the number.

We can also measure a factorial from the previous 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 :
9! Factorial = 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 = 9 × 8! = 362880

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