What is 90 factorial ?

Steps to calculate factorial of 90

How to calculate the factorial of 90

To find 90 factorial, or 90!, simply use the formula that multiplies the number 90 by all positive whole numbers less than it.

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

  90! is exactly : 1485715964481761497309522733620825737885569961284688766942216863704985393094065876545992131370884059645617234469978112000000000000000000000

  Factorial of 90 can be calculated as:
90! = 90 x 89 x 88 x 87 x ... x 3 x 2 x 1

  The number of trailing zeros in 90! is 21

  The number of digits in 90 factorial is 139.

What Is Factorial?

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

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

Symbolically, it is represented as "!".

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

Factorial Formula

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

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

The expansion of the formula gives the numbers to be replicated at the same time to get the factorial of the number.

We can also calculate 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 :
90! Factorial = 90 x 89 x 88 x 87 x ... x 3 x 2 x 1 = 90 × 89! = 1485715964481761497309522733620825737885569961284688766942216863704985393094065876545992131370884059645617234469978112000000000000000000000

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 own value is equal to 1. So, 0! = 1.

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