Divisor Sum of 65

Example of Divisor Sum of Non-Square Semiprime

 * $\map {\sigma_1} {65} = 84$

where $\sigma_1$ denotes the divisor sum function.

Proof
We have that:
 * $65 = 5 \times 13$

and so by definition is a semiprime whose prime factors are distinct.

Hence: