Java Exercises: Check if a number is Mersenne number or not

Java Numbers: Exercise-22 with Solution

Write a program to check if a number is Mersenne number or not.

In mathematics, a Mersenne number is a prime number that can be written in the form Mn = 2n − 1 for some integer n.
The first four Mersenne primes are 3, 7, 31, and 127

Test Data
Input a number: 127

Pictorial Presentation:

Java: Check if a number is Mersenne number or not.

Sample Solution:

Java Code:

import java.util.Scanner;
import java.math.BigInteger;
public class Example22 {

    public static void main(String args[])
        Scanner in = new Scanner(System.in);
        System.out.print("Input a number: ");
        int n = in.nextInt();
        int n1 = n + 1;

        int power = 0;
        int ans = 0;
        for(int i=0;;i++)
            else if(power==n1)
               System.out.println(n+" is a Mersenne number.");
   System.out.println(n+" is not a Mersenne number.");

Sample Output:

Input a number: 127                                                                                           
127 is a Mersenne number. 


Flowchart: Check if a number is Mersenne number or not

Java Code Editor:

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