Let n=pkn = p^kn=pk. For which of the following is the sum of divisors σ(n)\sigma(n)σ(n) a power of 222?
p=2,k=2p=2, k=2p=2,k=2
p=3,k=1p=3, k=1p=3,k=1
p=7,k=1p=7, k=1p=7,k=1
p=3,k=2p=3, k=2p=3,k=2