freeCodeCamp/curriculum/challenges/english/10-coding-interview-prep/project-euler/problem-132-large-repunit-factors.md

---
id: 5900f3f11000cf542c50ff03
title: 'Problem 132: Large repunit factors'
challengeType: 5
forumTopicId: 301760
dashedName: problem-132-large-repunit-factors
---

# --description--

A number consisting entirely of ones is called a repunit. We shall define $R(k)$ to be a repunit of length $k$.

For example, $R(10) = 1111111111 = 11 × 41 × 271 × 9091$, and the sum of these prime factors is 9414.

Find the sum of the first forty prime factors of $R({10}^9)$.

# --hints--

`largeRepunitFactors()` should return `843296`.

```js
assert.strictEqual(largeRepunitFactors(), 843296);
```

# --seed--

## --seed-contents--

```js
function largeRepunitFactors() {

  return true;
}

largeRepunitFactors();
```

# --solutions--

```js
// solution required
```