C program to print perfect numbers in the range 1 - user defined number

A perfect number is a positive integer which is equal to the sum of its divisors except the number itself. Examples of perfect numbers are: 6 and 28.

Below is a C program which allows a user to enter a number as input and print all the perfect numbers in the range 1 to the given number:

/*Program to print perfect numbers in the range 1 - user defined number*/
#include<stdio.h>
#include<conio.h>
main()
{
    int i,j,num,sum;
    clrscr();
    printf("Enter a number:");
    scanf("%d",&num);
    printf("\nPerfect numbers in the range 1 - %d are:\n",num);
    for(i=1;i<=num;i++)
    {
        sum = 0;
        /*Logic to check whether a number is perfect number or not*/
        for(j=1;j<i;j++)
        {
            if(i%j==0)
            {
                sum = sum + j;
            }
        }
        if(sum==i)
        {
            printf("%d\t",i);
        }
    }
    getch();
}


Sample input and output:

Enter a number: 100
Perfect numbers in the range 1 - 100 are:
6          28