# What is 64 factorial ?

Steps to calculate factorial of 64

## How to calculate the factorial of 64

To find 64 factorial, or 64!, simply use the formula that multiplies the number 64 by all positive whole numbers less than it.

Let's look at how to calculate the Factorial of Sixty-four :

64! is exactly : 126886932185884164103433389335161480802865516174545192198801894375214704230400000000000000

Factorial of 64 can be calculated as:
64! = 64 x 63 x 62 x 61 x ... x 3 x 2 x 1

The number of trailing zeros in 64! is 15

The number of digits in 64 factorial is 90.

## What Is Factorial?

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

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

Symbolically, it is listed as "!".

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

## Factorial Formula

To find the factorial of any given number, substitute 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 replicated to each other to receive the factorial of the number.

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

So the rule is : n! = n × (n−1)!

Example :
64! Factorial = 64 x 63 x 62 x 61 x ... x 3 x 2 x 1 = 64 × 63! = 126886932185884164103433389335161480802865516174545192198801894375214704230400000000000000

## 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.