freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/project-euler/problem-455-powers-with-trailing-digits.english.md

---
id: 5900f5331000cf542c510046
challengeType: 5
title: 'Problem 455: Powers With Trailing Digits'
---

## Description
<section id='description'>
Let f(n) be the largest positive integer x less than 109 such that the last 9 digits of nx form the number x (including leading zeros), or zero if no such integer exists.

For example:

f(4) = 411728896 (4411728896 = ...490411728896)
f(10) = 0
f(157) = 743757 (157743757 = ...567000743757)
Σf(n), 2 ≤ n ≤ 103 = 442530011399
Find Σf(n), 2 ≤ n ≤ 106.
</section>

## Instructions
<section id='instructions'>

</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler455()</code> should return 450186511399999.
    testString: assert.strictEqual(euler455(), 450186511399999, '<code>euler455()</code> should return 450186511399999.');

```

</section>

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

<div id='js-seed'>

```js
function euler455() {
  // Good luck!
  return true;
}

euler455();
```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```

</section>