If ppp is a prime number, what is the value of the sum ∑d∣p3ϕ(d)\sum_{d|p^3} \phi(d)∑d∣p3ϕ(d)?
p2p^2p2
p3p^3p3
p3−1p^3 - 1p3−1
p3−1p−1\frac{p^3-1}{p-1}p−1p3−1