The tutorial says that for a given prime no. P it’s s ( P) i.e. the sum of all it’s divisors is P (as prime no. Is divisible by only itself)

So S(P^2) = P+P^2

Let’s take an example let p=7

So S(7) = 7 as 7 is a prime no.

S(49)=S(7^2) = 7+49

As there are only two divisors of 49 , that are 7 and 49 itself

So S(P^a)=P+P^2+P^3 and so on till P^a

So the answer will be S(P1^a1)*S(P2^a2) and so on for n prime no.*

Now the let’s take an example in given sample test case of question

So S(2^2) = 2+4=6

S(3^1)=3

S(5^1)=5

So answer is (63*5)=90 which is the answer

Just a last elaboration:

For the question you have to find the sum of all no. With prime factor’s power starting with 1

So answer would be (2^2+2^1) * 3 * 5 for sample test case

Hope it helps you