freeCodeCamp/curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-211-divisor-square-sum.md

---
id: 5900f43f1000cf542c50ff52
title: 'Problem 211: Divisor Square Sum'
challengeType: 5
forumTopicId: 301853
dashedName: problem-211-divisor-square-sum
---

# --description--

For a positive integer $n$, let $σ_2(n)$ be the sum of the squares of its divisors. For example,

$$σ_2(10) = 1 + 4 + 25 + 100 = 130$$

Find the sum of all $n$, $0 < n < 64\\,000\\,000$ such that $σ_2(n)$ is a perfect square.

# --hints--

`divisorSquareSum()` should return `1922364685`.

```js
assert.strictEqual(divisorSquareSum(), 1922364685);
```

# --seed--

## --seed-contents--

```js
function divisorSquareSum() {

  return true;
}

divisorSquareSum();
```

# --solutions--

```js
// solution required
```