If $σ_k(n)$= Sum of kth powers of all the positive divisors of n, n ∈ N, the what is the value of $σ_3(9)$ ?
Answer & explanation
Correct answer: option 2
The correct answer is option (2) : 757
$σ_3(9)$
Positive divisions of 9 are $1,3, 9$
$∴σ_3(9)=1^3+3^3+9^3$
$1+27+729$
$=757$