freeCodeCamp/curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-401-sum-of-squares-of-divisors.md

id, title, challengeType, forumTopicId, dashedName

id	title	challengeType	forumTopicId	dashedName
5900f4fd1000cf542c51000f	Problem 401: Sum of squares of divisors	5	302069	problem-401-sum-of-squares-of-divisors

--description--

The divisors of 6 are 1, 2, 3 and 6.

The sum of the squares of these numbers is 1 + 4 + 9 + 36 = 50.

Let \sigma_2(n) represent the sum of the squares of the divisors of n. Thus \sigma_2(6) = 50.

Let \Sigma_2 represent the summatory function of \sigma_2, that is \Sigma_2(n) = \sum \sigma_2(i) for i=1 to n. The first 6 values of \Sigma_2 are: 1, 6, 16, 37, 63 and 113.

Find \Sigma_2({10}^{15}) modulo {10}^9.

--hints--

sumOfSquaresDivisors() should return 281632621.

assert.strictEqual(sumOfSquaresDivisors(), 281632621);

--seed--

--seed-contents--

function sumOfSquaresDivisors() {

  return true;
}

sumOfSquaresDivisors();

--solutions--

// solution required