Problem Archive

Let $f(n)$ be the number of couples $(x, y)$ with $x$ and $y$ positive integers, $x \le y$ and the least common multiple of $x$ and $y$ equal to $n$.

Let $g$ be the summatory function of $f$, i.e.: $g(n) = \sum f(i)$ for $1 \le i \le n$.

You are given that $g(10^6) = 37429395$.

Find $g(10^{12})$.