AMO · 2027 · Grades 6-7 · Self-study SET 30 Question 8

For example, $2^5=2\times2\times2\times2\times2$. If $4096=a^b$, find the sum of all possible values of $a$, where $a$ is a positive integer and $b$ is a whole number greater than 1.

**Input:** Choose one option.