Untitled

#include <stdio.h>

int main()
{
    unsigned int num;
    scanf("%u",&num);
    for (unsigned int j = num ; j > 0 ; j--)
    {
        // defining variables
        unsigned int  sum = 0;
    
        // loop to get all proper divisors
        // it is sufficient to loop until num/2, because after that there will not be other proper divisors!
        for (int i = 1; i <= j / 2; i++)
        {
            if (j % i == 0) // if the number can be divided by the current divisor 'i'
                sum += i; // then add 'i' to the running sum
        }
        // at the end of the loop, check if num is equal to sum
        if (j == sum)
            printf("%u\n",j);
    }
}