# 0263. Ugly Number

<https://leetcode.com/problems/ugly-number>

## Description

An **ugly number** is a positive integer whose prime factors are limited to `2`, `3`, and `5`.

Given an integer `n`, return `true` *if* `n` *is an **ugly number***.

**Example 1:**

```
**Input:** n = 6
**Output:** true
**Explanation:** 6 = 2 × 3
```

**Example 2:**

```
**Input:** n = 8
**Output:** true
**Explanation:** 8 = 2 × 2 × 2
```

**Example 3:**

```
**Input:** n = 14
**Output:** false
**Explanation:** 14 is not ugly since it includes the prime factor 7.
```

**Example 4:**

```
**Input:** n = 1
**Output:** true
**Explanation:** 1 has no prime factors, therefore all of its prime factors are limited to 2, 3, and 5.
```

**Constraints:**

* `-231 <= n <= 231 - 1`

## ac

```java
public boolean isUgly(int num) {
    if(num==1) return true;
    if(num==0) return false;
    while(num%2==0) num=num/2;
    while(num%3==0) num=num/3;
    while(num%5==0) num=num/5;
    return num==1;
}
```

<https://leetcode.com/problems/ugly-number/discuss/69225/My-2ms-java-solution>


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