Suma Divizorilor Pari

#include <iostream>
using namespace std;

int main()
{
    unsigned long long n,s=0;
    cin>>n;
    unsigned long long d;
	for(d=1 ; d*d<n ; d++)
		if(n % d == 0)
        {
			if(d%2==0)
				s+=d;
			if(n/d%2==0)
				s+=n/d;
		}
	if(d * d == n)
		if(d%2==0)
			s+=d;
    cout<<s;
    return 0;
}