Abundant Number Program in Java (With Explanation & Dry Run)

📌 Introduction

In Java number programs, Abundant Number is an important topic often asked in BCA exams, viva, and interviews.
In this article, you will learn what an abundant number is, how to check it using Java, along with clear explanation and dry run.

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🔢 What Is an Abundant Number?

A number is called an Abundant Number if the sum of its proper divisors is greater than the number itself.

👉 Proper divisors are the divisors excluding the number itself.

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🧠 Example of Abundant Number

Example 1

Number = 12
Proper divisors = 1, 2, 3, 4, 6
Sum = 1 + 2 + 3 + 4 + 6 = 16

Since 16 > 12,
✅ 12 is an Abundant Number

Example 2

Number = 8
Proper divisors = 1, 2, 4
Sum = 7

Since 7 < 8,
❌ 8 is NOT an Abundant Number

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🧩 Algorithm to Check Abundant Number

1. Start

2. Read a number

3. Initialize sum = 0

4. Find all divisors from 1 to number/2

5. If divisor divides number completely, add it to sum

6. If sum > number → Abundant Number

7. Else → Not Abundant

8. End

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💻 Java Program to Check Abundant Number

import java.util.Scanner;

public class AbundantNumber {
    public static void main(String[] args) {
        int number, sum = 0;

        Scanner sc = new Scanner(System.in);
        System.out.print("Enter a number: ");
        number = sc.nextInt();

        for (int i = 1; i <= number / 2; i++) {
            if (number % i == 0) {
                sum = sum + i;
            }
        }

        if (sum > number) {
            System.out.println(number + " is an Abundant Number");
        } else {
            System.out.println(number + " is NOT an Abundant Number");
        }
    }
}

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🧪 Dry Run

Input

number = 12
sum = 0

i	Divides 12?	sum
1	Yes	1
2	Yes	3
3	Yes	6
4	Yes	10
6	Yes	16

Final Check

sum = 16 > 12

✅ 12 is an Abundant Number

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🖥️ Output

Enter a number: 12
12 is an Abundant Number

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📚 Types of Numbers (For Better Understanding)

Type	Condition
Perfect Number	Sum of divisors = number
Deficient Number	Sum of divisors < number
Abundant Number	Sum of divisors > number

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🎯 Important Exam Points

• Proper divisors exclude the number itself

• Loop runs till number/2

• Time Complexity: O(n)

• Common examples: 12, 18, 20, 24