Java: Check whether a given number is an ugly number

Last update on May 15 2025 13:10:49 (UTC/GMT +8 hours)

Check Ugly Number

Write a Java program to check whether a given number is ugly.

In number system, ugly numbers are positive numbers whose only prime factors are 2, 3 or 5. First 10 ugly numbers are 1, 2, 3, 4, 5, 6, 8, 9, 10, 12. By convention, 1 is included.

Test Data: Input an integer number: 235

Pictorial Presentation:

Sample Solution:

Java Code:

import java.util.Scanner;
public class Exercise1 {
       public static void main(String[] args){
        Scanner in = new Scanner(System.in);
        System.out.print("Input an integer number: ");
        int n = in.nextInt();  		
        if (n <= 0) {
            System.out.print("Input a correct number.");
        }
		int x = 0;
        while (n != 1) {
            if (n % 5 == 0) {
                n /= 5;
            } else if (n % 3 == 0) {
                n /= 3;
            } else if (n % 2 == 0) {
                n /= 2;
            } else {
                System.out.print("It is not an ugly number.");
				x = 1;
				break;
            }
        }
        if (x==0)
		System.out.print("It is an ugly number.");
		System.out.print("\n");
	    }
}

Sample Output:

Input an integer number: 235                                                                                  
It is not an ugly number.

Flowchart:

For more Practice: Solve these Related Problems:

• Write a Java program to recursively check if a number is ugly by continuously dividing it by 2, 3, and 5.
• Write a Java program to generate all ugly numbers up to a specified limit using dynamic programming.
• Write a Java program to verify the ugly number property by performing prime factorization and ensuring only 2, 3, and 5 are factors.
• Write a Java program to count the total number of ugly numbers in a given array using iterative methods.

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Java Code Editor:

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