C++ Factorial Finder Recursive Function

#include <iostream>

using namespace std;

double f(double x)
{
    if(x == 1) // base case
    {
        return 1;
    }
    else
    {
        return x * f(x-1); // recursion case
    }
}

int main()
{
    // Test:
    cout << f(170); // the biggest number for C++ to calculate the factorial of
}