Product of Two Distinct Primes is Multiplicatively Perfect
Then $n$ is multiplicatively perfect.
Let $n = p \times q$ where $p$ and $q$ are primes.
From Product of Two Distinct Primes has 4 Positive Divisors, the positive divisors of $n$ are:
- $1, p, q, pq$
- $1 \times p \times q \times p q = p^2 q^2 = n^2$
Hence the result, by definition of multiplicatively perfect.