data/problems/401.yml
---
:id: 401
:name: Sum of squares of divisors
:url: https://projecteuler.net/problem=401
:content: "The divisors of 6 are 1,2,3 and 6. \nThe sum of the squares of these numbers
is 1+4+9+36=50.\n\nLet sigma2(n) represent the sum of the squares of the divisors
of n. Thus sigma2(6)=50.\n\nLet SIGMA2 represent the summatory function of sigma2,
that is SIGMA2(n)=∑sigma2(i) for i=1 to n. \nThe first 6 values of SIGMA2 are:
1,6,16,37,63 and 113.\n\nFind SIGMA2(10<sup>15</sup>) modulo 10<sup>9</sup>.\n\n"