# What is the factorial of hundred?

Before we look for the answer for 100 factorial, let us try to understand what is factorial. Factorial is actually the product of the positive integers which are less or equal to certain positive integers. This is generally denoted with “n”. So, a factorial 100 is all the positive numbers comprising zero.

You must also note that this can be equal to or less than n but would be equals to or greater than 1. However, factorials are not generally defined for negative numbers. This system is mostly used in math while making calculations of permutations and combinations. This system mostly can be seen as a sequence where you can find descending natural numbers that are in multiplication. For an example 9 x 8 x 7 x 6 x ….. 1.
!” is the symbol used for factorials. So let us have a look at the 100 factorial value.

## The factorial formula:

If n is a natural number greater than or equal to 1, then
n! = n x (n – 1) x (n – 2) x (n – 3) … 3 x 2 x 1
If n = 0, then n! = 1, by convention.

## Below is Java implementation:

``````import java.util.*;
import java.lang.*;
import java.io.*;
import java.math.*;

class FacorialOfBigNuumber
{
public static void main (String[] args) throws java.lang.Exception
{
BigInteger fact= BigInteger.ONE;
int factorialNo = 100;

for (int i = 2; i <= factorialNo; i++)
{
fact = fact.multiply(new BigInteger(String.valueOf(i)));
}

System.out.println("The factorial of " + factorialNo +" is: " + fact);
}
}``````

The factorial of 100 is 9332621544394415268169923885626670049071596826438162 14685929638952175999932299156089414639761565182862536979208272237582511 85210916864000000000000000000000000