Write a c program to check whether a given number is a perfect number or not.

Perfect number  

in mathematics, perfect number is a positive integer that is equal to the sum of its positive divisors, excluding the number itself. For instance, 6 has divisors 1, 2 and 3 (excluding itself), and 1 + 2 + 3 = 6, so 6 is a perfect number. Let's see the following example  

 

QUESTION:- Write a c program to check whether a given number is a perfect number or not.

Test Data : 

Input the number: 56 

Expected Output : 

The positive divisor: 1 2 4 7 8 14 28 

The sum of the divisor is: 64 

So, the number is not perfect. 

#include <stdio.h>

#include <conio.h>

void main()

{

    int no, sum = 0;

    printf("enter a value: ");

    scanf("%d", &no);

    for (int i = 1; i <= (no / 2); i++)

    {

        if (no % i == 0)

        {

            sum = sum + i;

        }

    }

    if (sum == no)

    {

        printf("%d is perfect number with sum %d ", no, sum);

    }

    else

    {

        printf("%d is not a perfect number with sum %d ", no, sum);

    }

}

OUTPUT

enter a value: 10

10 is not a perfect number with a sum of 8 

Follow our page for regular updates.