---
id: 5900f4291000cf542c50ff3a
challengeType: 5
title: 'Problem 187: Semiprimes'
forumTopicId: 301823
---
## Description
A composite is a number containing at least two prime factors. For example, 15 = 3 × 5; 9 = 3 × 3; 12 = 2 × 2 × 3.
There are ten composites below thirty containing precisely two, not necessarily distinct, prime factors:
4, 6, 9, 10, 14, 15, 21, 22, 25, 26.
How many composite integers, n < 108, have precisely two, not necessarily distinct, prime factors?
## Instructions
## Tests
```yml
tests:
- text: euler187() should return 17427258.
testString: assert.strictEqual(euler187(), 17427258);
```
## Challenge Seed
```js
function euler187() {
// Good luck!
return true;
}
euler187();
```