---
id: 5900f4651000cf542c50ff77
challengeType: 5
title: 'Problem 248: Numbers for which Euler’s totient function equals 13!'
videoUrl: ''
localeTitle: 问题248：Euler的totient函数等于13的数字！
---

## Description
<section id="description"> φ（n）= 13的第一个数字n！是6227180929.找到第150,000个这样的数字。 </section>

## Instructions
<section id="instructions">
</section>

## Tests
<section id='tests'>

```yml
tests:
  - text: <code>euler248()</code>应返回23507044290。
    testString: 'assert.strictEqual(euler248(), 23507044290, "<code>euler248()</code> should return 23507044290.");'

```

</section>

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

<div id='js-seed'>

```js
function euler248() {
  // Good luck!
  return true;
}

euler248();

```

</div>



</section>

## Solution
<section id='solution'>

```js
// solution required
```
</section>