# What is 85 factorial ?

Steps to calculate factorial of 85

## How to calculate the factorial of 85

To find 85 factorial, or 85!, simply use the formula that multiplies the number 85 by all positive whole numbers less than it.

Let's look at how to calculate the Factorial of Eighty-five :

85! is exactly : 281710411438055027694947944226061159480056634330574206405101912752560026159795933451040286452340924018275123200000000000000000000

Factorial of 85 can be calculated as:
85! = 85 x 84 x 83 x 82 x ... x 3 x 2 x 1

The number of trailing zeros in 85! is 20

The number of digits in 85 factorial is 129.

## What Is Factorial?

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

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

Symbolically, it is listed as "!".

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

## Factorial Formula

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

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

The expansion of the formula provides the numbers to be replicated collectively to receive the factorial of the number.

We can also work out 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 :
85! Factorial = 85 x 84 x 83 x 82 x ... x 3 x 2 x 1 = 85 × 84! = 281710411438055027694947944226061159480056634330574206405101912752560026159795933451040286452340924018275123200000000000000000000

## 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.