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# Factorial Program in Java

Hey folks, today in this blog you’ll see Factorial Program in Java. I have created blogs on making a Group Chat APP Using JAVA and in this fantastic blog, you will learn how to create a Factorial Program in Java. So, Factorial Program in Java: Factorial of n is the product of all positive descending integers. Factorial of n is denoted by n!.For example:
```6! = 720 7! = 5040```

Here, 6! is pronounced as “6 factorial”, it is also called “6 bang” or “6 shrieks”.

The factorial is normally used in Combinations and Permutations (mathematics).

The factorial of a positive number n is given by:
`factorial of n (n!) = 1 * 2 * 3 * 4 * ... * n`

There are many ways to write the factorial program in java language. Let’s see the 3 ways to write the factorial program in java.

You might like this:

Example 1: Find the Factorial of a number using BigInteger
`import java.math.BigInteger;

public class Factorial {

``````public static void main(String[] args) {

int num = 30;
BigInteger factorial = BigInteger.ONE;
for(int i = 1; i <= num; ++i)
{
// factorial = factorial * i;
factorial = factorial.multiply(BigInteger.valueOf(i));
}
System.out.printf("Factorial of %d = %d", num, factorial);
}
``````

}`

Here, instead of long, we use BigInteger variable factorial.

Since * cannot be used with BigInteger, we instead use multiply() for the product. Also, num should be cast to BigInteger not long for multiplication.