# What is 42 factorial ?

Steps to calculate factorial of 42

## How to calculate the factorial of 42

To find 42 factorial, or 42!, simply use the formula that multiplies the number 42 by all positive whole numbers less than it.

Let's look at how to calculate the Factorial of Forty-two :

42! is exactly : 1405006117752879898543142606244511569936384000000000

Factorial of 42 can be calculated as:
42! = 42 x 41 x 40 x 39 x ... x 3 x 2 x 1

The number of trailing zeros in 42! is 10

The number of digits in 42 factorial is 52.

## What Is Factorial?

A factorial is symbolized by an integer and an exclamation symbol. In math concepts, factorial is a multiplication procedure 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 items can be established .

## Factorial Formula

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

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

The expansion of the formula gives the numbers to be replicated to each other to find the factorial of the number.

We can also work out 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 :
42! Factorial = 42 x 41 x 40 x 39 x ... x 3 x 2 x 1 = 42 × 41! = 1405006117752879898543142606244511569936384000000000

## 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 equal to 1. So, 0! = 1.