check input number is perfect number ?

main.c

#include <stdio.h>

int isperfect(int input)
{
    int sum = 0, value = input / 2;
    do
    {
        if (input % value == 0)
            sum += value;
        value--;
    } while (value);
    if (input == sum)
        return 1;
    else
        return 0;
}

int main()
{
    unsigned long long number;
    printf("Enter any number: ");
    scanf("%llu", &number);
    int j;
    j = number + 10;
    printf("entered number is %d\n", number);
    for (number; number < j; number++)
    {

        if (isperfect(number) == 1)
        {
            printf("%d is it perfect\n", number);
        }
        else if (isperfect(number) == 0)
        {
            printf("%d is not perfect\n", number);
        }
    }

    return 0;
}