Java Program To Find LCM for Two Large Numbers

A quick example guide to find the lcm for two large numbers in java using BigInteger.

1.Overview

In this short article, you'll learn how to find the LCM for two large numbers. Here, we are going to use BigInteger class to hold the large values.

Example:

large value 1: 123456789123456789123456

large value 2: 987654321987654321987654

Output lcm : 20322105226083421931844602115480285409718968704

2. Example To Find LCM for Large Numbers

Let us use the two BigInteger object to hold the large values.

This BigInteger class has gcd() method which returns GCD for two numbers.

Next, use multiply() method to get the multiplication of two numbers.

Finally, use the formula LCM = large 1 * large 2 / gcd(large1 * large 2)

package com.javaprogramto.programs.maths;

import java.math.BigInteger;

public class LCMOfLargeNumbers {

	public static void main(String[] args) {
		
		BigInteger large1 = new BigInteger("123456789123456789123456");
		BigInteger large2 = new BigInteger("987654321987654321987654");

		BigInteger gcd = large1.gcd(large2);
		
		BigInteger multiply = large1.multiply(large2);
		
		BigInteger lcm = multiply.divide(gcd);
		
		System.out.println("Final LCM output: "+lcm.toString());
	
	}
}

Output:

Final LCM output: 20322105226083421931844602115480285409718968704

3. Conclusion

In this article, you've seen how to find the right lcm for bigger values using BigInteger class methods.

BigInteger API

GitHub Example