---
id: 5900f4651000cf542c50ff77
challengeType: 5
title: 'Problem 248: Numbers for which Euler’s totient function equals 13!'
---
## Description
The first number n for which φ(n)=13! is 6227180929.
Find the 150,000th such number.
## Instructions
## Tests
```yml
tests:
- text: euler248() should return 23507044290.
testString: assert.strictEqual(euler248(), 23507044290, 'euler248() should return 23507044290.');
```
## Challenge Seed
```js
function euler248() {
// Good luck!
return true;
}
euler248();
```