Just loop from Div = N - 1 to 1 and check if that N % Div is zero. If it is then print Div. Feel free to use my code as an example, but you aren't allowed to use it for any educational credits.
Code:
/* (c) Copyright 2002 Daniel Raxter, All Rights Reserved. */
#include <stdio.h>
#include <stdlib.h>
void ListProperDivs (int N)
{
int Div = N;
while (--Div > 0){
if ((N % Div) == 0)
printf ("%d ", Div);
}
}
int main (void)
{
int N;
printf ("Enter a number: ");
if (scanf ("%d", &N) != 1){
fprintf (stderr, "Bad Input\n");
exit (EXIT_FAILURE);
}
/* Okay so far */
ListProperDivs (N);
return (EXIT_SUCCESS);
}