# 1952. Three Divisors

https://leetcode.com/problems/three-divisors

## Description

Given an integer `n`, return `true` _if_ `n` _has **exactly three positive divisors**. Otherwise, return_ `false`.

An integer `m` is a **divisor** of `n` if there exists an integer `k` such that `n = k * m`.

**Example 1:**

```
**Input:** n = 2
**Output:** false
**Explantion:** 2 has only two divisors: 1 and 2.
```

**Example 2:**

```
**Input:** n = 4
**Output:** true
**Explantion:** 4 has three divisors: 1, 2, and 4.
```

**Constraints:**

* `1 <= n <= 104`

## ac

```java
```
