Pefect Number checking.

perfect_number.c

#include <stdio.h>

int main() {
	int num, rem; 
	int sum = 0;
	int i;

	printf("Enter a number: ");
	scanf("%d", &num);

	for (i = 1; i <= (num - 1); i++) {


		rem = num % i;
		if (rem == 0) {
			sum = sum + i;
		}

	}
	
	if (sum == num) {
		printf("\nThis is a perfect number.");
		
	}
	else {
		printf("\nThis is not a perfect number.");
	}

	return 0;
}