---
id: 5900f4181000cf542c50ff2a
challengeType: 5
title: 'Problem 171: Finding numbers for which the sum of the squares of the digits is a square'
---
## Description
For a positive integer n, let f(n) be the sum of the squares of the digits (in base 10) of n, e.g.
f(3) = 32 = 9,
f(25) = 22 + 52 = 4 + 25 = 29,
f(442) = 42 + 42 + 22 = 16 + 16 + 4 = 36
Find the last nine digits of the sum of all n, 0 < n < 1020, such that f(n) is a perfect square.
## Instructions
## Tests
```yml
tests:
- text: euler171() should return 142989277.
testString: assert.strictEqual(euler171(), 142989277, 'euler171() should return 142989277.');
```
## Challenge Seed
```js
function euler171() {
// Good luck!
return true;
}
euler171();
```