Euler Totient x Geometric Series

For each positive integer $n$, let $\varphi(n)$ be the number of positive integers from $1$ to $n$ that are relatively prime to $n$. Evaluate: \[ \sum_{n=1}^\infty \varphi(n)\left(\frac{4^n}{7^n-4^n}\right) \] The answer is in the form $\frac{\alpha}{\beta}$ for coprime positive integers $\alpha$ and $\beta$. Input the answer as the sum $\alpha +\beta$.