Java Program To Check If A Given Number is A Perfect Number

Description

Perfect number is a positive integer that is equal to the sum of its proper positive divisors, that is, the sum of its positive divisors excluding the number itself. Following are the examples of perfect number.

6= 1+2+3
28= 1+2+4+7+14
496= 1+2+4+8+16+31+62+124+248

Following is the java program to check if a given number is a perfct number or not.

package com.devglan.set1;

public class PerfectNumber {

    public void checkPerfectNumber(int num){
        int divisorSum = 1;
        for(int i = 2; i <= num/2; i++)
            if(num % i == 0)
                divisorSum += i;

        if(divisorSum == num) {
            System.out.print("Given number " + num + " is a perfect number.");
        }else {
            System.out.print("Given number " + num + " is not a perfect number.");
        }
    }

    public static void main(String [] args){
        PerfectNumber perfectNumber = new PerfectNumber();
        perfectNumber.checkPerfectNumber(28);
    }
}