---
id: 5900f48f1000cf542c50ffa1
challengeType: 5
title: 'Problem 290: Digital Signature'
---
## Description
How many integers 0 ≤ n < 1018 have the property that the sum of the digits of n equals the sum of digits of 137n?
## Instructions
## Tests
```yml
tests:
- text: euler290() should return 20444710234716470.
testString: assert.strictEqual(euler290(), 20444710234716470, 'euler290() should return 20444710234716470.');
```
## Challenge Seed
```js
function euler290() {
// Good luck!
return true;
}
euler290();
```