C Program to Check whether a given Number is Perfect Number

A perfect number is a number which is equal to the sum of its divisor. For eg, divisors of 6 are 1,2, and 3. The sum of these divisors is 6. So 6 is called a perfect number.

PROGRAM:

#include<stdio.h>

int main() 

{

    int sum=0,i,n;

    scanf("%d",&n);

    for(i=1;i<=n-1;i++)

    {

        if(n%i==0)

        sum=sum+i;

    }

    if(sum==n)

        printf("It is a perfect number");

    else

    printf("Not a perfect number");

    return 0;

}

OUTPUT:

6                                                                                                                     

It is a perfect number