### C# Basic

### C# Interview Programs

- C# Interview Programs
- C# Abundant Number
- C# Amicable Number
- C# Armstrong Number
- C# Average of N Numbers
- C# Automorphic Number
- C# Biggest of three numbers
- C# Binary to Decimal
- C# Common Divisors
- C# Composite Number
- C# Condense a Number
- C# Cube Number
- C# Decimal to Binary
- C# Decimal to Octal
- C# Disarium Number
- C# Even Number
- C# Evil Number
- C# Factorial of a Number
- C# Fibonacci Series
- C# GCD
- C# Happy Number
- C# Harshad Number
- C# LCM
- C# Leap Year
- C# Magic Number
- C# Matrix Addition
- C# Matrix Division
- C# Matrix Multiplication
- C# Matrix Subtraction
- C# Matrix Transpose
- C# Maximum Value of an Array
- C# Minimum Value of an Array
- C# Multiplication Table
- C# Natural Number
- C# Number Combination
- C# Odd Number
- C# Palindrome Number
- C# Pascalβs Triangle
- C# Perfect Number
- C# Perfect Square
- C# Power of 2
- C# Power of 3
- C# Pronic Number
- C# Prime Factor
- C# Prime Number
- C# Smith Number
- C# Strong Number
- C# Sum of Array
- C# Sum of Digits
- C# Swap Two Numbers
- C# Triangular Number

# C# Program to Check Perfect Number

Photo Credit to CodeToFun

## π Introduction

In the realm of programming, exploring the properties of numbers is a fascinating task. One such special type of number is a perfect number.

A perfect number is a positive integer that is equal to the sum of its proper divisors (excluding itself).

In this tutorial, we will delve into a C# program designed to check whether a given number is a perfect number.

The program involves identifying the divisors of the number and determining if their sum equals the original number.

## π Example

Let's dive into the C# code that accomplishes this task.

```
using System;
class PerfectNumberChecker {
// Function to check if a number is a perfect number
static bool IsPerfectNumber(int number) {
int sum = 1; // Initialize sum with 1 (as 1 is always a divisor)
// Iterate from 2 to the square root of the number
for (int i = 2; i <= Math.Sqrt(number); i++) {
if (number % i == 0) {
// If i is a divisor, add both divisors if they are different
if (i == (number / i))
sum += i;
else
sum += (i + number / i);
}
}
// If the sum of divisors is equal to the original number, it is a perfect number
return (sum == number);
}
// Driver program
static void Main() {
// Replace this value with the number you want to check
int number = 28;
// Call the function to check if the number is a perfect number
if (IsPerfectNumber(number))
Console.WriteLine($"{number} is a perfect number.");
else
Console.WriteLine($"{number} is not a perfect number.");
}
}
```

### π» Testing the Program

To test the program with different numbers, modify the value of number in the Main method.

28 is a perfect number.

### π§ How the Program Works

- The program defines a class PerfectNumberChecker containing a static method IsPerfectNumber that takes an integer number as input and returns true if the number is a perfect number, and false otherwise.
- Inside the Main method, replace the value of number with the desired number you want to check.
- The program calls the IsPerfectNumber method and prints the result using Console.WriteLine.

## π Between the Given Range

Let's delve into the C# code that identifies perfect numbers in the specified range.

```
using System;
class Program {
// Function to check if a number is perfect
static bool IsPerfectNumber(int num) {
int sum = 0;
// Iterate through potential divisors up to half of the number
for (int i = 1; i <= num / 2; i++) {
if (num % i == 0) {
sum += i;
}
}
// Check if the sum of divisors is equal to the number
return sum == num;
}
// Driver program
static void Main() {
Console.Write("Perfect Numbers in the range 1 to 50: \n");
// Iterate through the range and check for perfect numbers
for (int i = 1; i <= 50; i++) {
if (IsPerfectNumber(i)) {
Console.Write($"{i} ");
}
}
Console.WriteLine();
}
}
```

### π» Testing the Program

Perfect Numbers in the range 1 to 50: 6 28

Run the program to see the perfect numbers in the specified range.

### π§ How the Program Works

- The program defines a function IsPerfectNumber that checks if a given number is perfect.
- Inside the function, it iterates through potential divisors up to the square root of the number, summing up proper divisors.
- The Main function iterates through the range from 1 to 50 and prints the perfect numbers.

## π§ Understanding the Concept of Perfect Number

Before delving into the code, let's understand the concept of perfect numbers. A perfect number is a positive integer that is equal to the sum of its proper divisors (excluding itself).

## π’ Optimizing the Program

While the provided program is effective, consider exploring and implementing alternative approaches or optimizations for checking perfect numbers.

Feel free to incorporate and modify this code as needed for your specific use case. Happy coding!

## π¨βπ» Join our Community:

## Author

For over eight years, I worked as a full-stack web developer. Now, I have chosen my profession as a full-time blogger at codetofun.com.

Buy me a coffee to make codetofun.com free for everyone.

Buy me a Coffee
If you have any doubts regarding this article (

C# Program to Check Perfect Number), please comment here. I will help you immediately.