freeCodeCamp/curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-248-numbers-for-which-eulers-totient-function-equals-13.md

---
id: 5900f4651000cf542c50ff77
title: 'Problem 248: Numbers for which Euler’s totient function equals 13!'
challengeType: 5
forumTopicId: 301895
dashedName: problem-248-numbers-for-which-eulers-totient-function-equals-13
---

# --description--

The first number $n$ for which $φ(n) = 13!$ is $6\\,227\\,180\\,929$.

Find the ${150\\,000}^{\text{th}}$ such number.

# --hints--

`eulersTotientFunctionEquals()` should return `23507044290`.

```js
assert.strictEqual(eulersTotientFunctionEquals(), 23507044290);
```

# --seed--

## --seed-contents--

```js
function eulersTotientFunctionEquals() {

  return true;
}

eulersTotientFunctionEquals();
```

# --solutions--

```js
// solution required
```