C-Program to Print all Perfect number between 1 and given number

#include<stdio.h>

#include<math.h>

int main()

{

  int num,i,sum,j;

  printf("Enter a number to know all perfect numbers till n\n");

  scanf("%d",&num);

  printf("The perfect numbers between 1 and %d are:",num);

  for(i=1;i<=num;i++)

  {

    sum=0;

    for(j=1;j<i;j++)

    {

      if(i%j==0)

      {

        sum+=j;

      }

    }

    if(sum==i)

    {

      printf("%d\n",i);

    }

  }

return 0;

}