# Perfect number or not using Java

## Perfect number or not using java :

Perfect number is a number whose sum of factors is equal to the given number. Let us consider an example for better understanding.

Example :

• Suppose a number  is 28 ;
• Factors of 28 are : 1, 2, 4, 7, 14 ;
• Sum of Factors of the number  = 28 ;

Here the sum of factors of the number is equal to the given number ;

So, 28 is a Perfect Number.

In this article we will create a java program to check whether a given number is a Perfect number or not. ### Working :

Step 1 : Ask the user to enter a number.

Step 2 : Declare a variable for storing sum.

Step 3 : Use a loop to find the factors of the given number and store its sum.

Step 4 : Calculate the sum of factors of the given number.

Step 5 : Compare whether the sum is equal to the given number or not.

• If both numbers are equal, then the given number is Perfect Number.
• Else the number is not a Perfect Number.

### Code in Java :

`//Java program to check whether a number is perfect or not import java.util.Scanner;public class perfect_number_or_not{		public static void main(String[] args)	{		//scanner class declaration		Scanner sc = new Scanner(System.in);		//input from user		System.out.print("Enter a number : ");						int number = sc.nextInt();		//declare a variable to store sum of factors		int sum = 0;		for(int i = 1 ; i < number ; i++)		{			if(number % i == 0)				sum = sum + i;		}		//comparing whether the sum is equal to the given number or not		if(sum == number)			System.out.println("Perfect Number");		else			System.out.println("Not an Perfect Number");		//closing scanner class(not compulsory, but good practice)		sc.close();														}}`

### Output :

`Enter a number : 6Perfect NumberEnter a number : 15Not an Perfect NumberEnter a number : 496Perfect Number`