#include <stdio.h>
#include <math.h>
int divisors(unsigned long long int n){
unsigned long long int l
= (unsigned long long int)sqrt(n
); int c=0;
for(unsigned long long int i=1;i<=l;i++){
if((n%i)==0) {
c++;
if(i!=(n/i))
c++;
}
}
return c;
}
int main(void) {
unsigned long long int n = 1;
unsigned long long int d = 1;
while (divisors(d) <= 500) {
n++;
d+= n;
}
}
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