Write a program to find perfect number or not.

Description:

A 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. Equivalently, a perfect number is a number that is half the sum of all of its positive divisors. The first perfect number is 6, because 1, 2 and 3 are its proper positive divisors, and 1 + 2 + 3 = 6. Equivalently, the number 6 is equal to half the sum of all its positive divisors: ( 1 + 2 + 3 + 6 ) / 2 = 6.

Code:

? 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 package com.govindsblog.algos;   public class IsPerfectNumber {       public boolean isPerfectNumber(int number){                   int temp = 0;         for(int i=1;i<=number/2;i++){             if(number%i == 0){                 temp += i;             }         }         if(temp == number){             System.out.println("It is a perfect number");             return true;         } else {             System.out.println("It is not a perfect number");             return false;         }     }           public static void main(String a[]){         IsPerfectNumber ipn = new IsPerfectNumber();         System.out.println("Is perfect number: "+ipn.isPerfectNumber(28));     } }

Output:

28 It is a perfect number Is perfect number: true