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

---
id: 5900f43f1000cf542c50ff52
challengeType: 5
isHidden: false
title: 'Problem 211: Divisor Square Sum'
forumTopicId: 301853
---

## Description
<section id='description'>
For a positive integer n, let σ2(n) be the sum of the squares of its divisors. For example,
σ2(10) = 1 + 4 + 25 + 100 = 130.
Find the sum of all n, 0 < n < 64,000,000 such that σ2(n) is a perfect square.
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler211()</code> should return 1922364685.
    testString: assert.strictEqual(euler211(), 1922364685);

```

</section>

## Challenge Seed
<section id='challengeSeed'>

<div id='js-seed'>

```js
function euler211() {
  // Good luck!
  return true;
}

euler211();
```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```

</section>