Counting the number of multiples of number A that perfectly divides the number B

Question

What is the best way of counting the number of multiples of number A that perfectly divides the number B.

This is the sub problem for one of the questions I am solving on codechef. This is the best I could come up with.

int func(int A,int B){
    int res = 0;
    int i = 1;
    while(A * i <= B){
        if(!(B %(A * i))){
            res++;
        }
        i++;
    }
    return res;
}

However,this is timing out for some of the cases. I am told that this can solved in O(sqrt(n)). Any help would be appreciated.