# C# Program to Check Perfect Number

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## What is Perfect Number?

A positive integer that is equal to the sum of its proper divisors.

For example, 6 is a perfect number
6 = 1 + 2 + 3
6 = 6

Tips: It is recommended to use our online Perfect Number calculator for better understanding.

## Check Perfect Number

In the following example, we will check whether the given number (496) is a Perfect number or not.

### Example

C# Compiler
using System; namespace myApp { class Program { static void Main(string[] args) { int num = 496; int i = 1; int total = 0; for(i=1; i<num; i++) { if(num % i == 0) total += i; } if(total == num) Console.Write("{0} is a perfect number", num); else Console.Write("{0} is not a perfect number", num); } } }

### Output

496 is a perfect number

## Perfect Numbers between the Given Range

In the following example, we will find all the Perfect numbers between 1 and 1000.

### Example

C# Compiler
using System; namespace myApp { class Program { static void Main(string[] args) { int start = 1; int end = 1000; int i = 1; int total = 0; int flag = 0; Console.Write("Perfect numbers between {0} and {1}:\n", start, end); for(start=start; start<=end; start++) { for(i=1; i<start; i++) { if(start % i == 0) total += i; } if((total == start) && (start != 0)) { flag = 1; Console.Write(start+" "); } total = 0; } if(flag == 0) Console.Write("There in no perfect number between the given range"); } } }

### Output

Perfect numbers between 1 and 1000: 6 28 496

## Check Whether the Given Number is Perfect or Not

In the following example, we will check whether the given number is a Perfect Number or Not.

### Example

C# Compiler
using System; namespace myApp { class Program { static void Main(string[] args) { Console.Write("Enter a (int) number: "); int num = Convert.ToInt32(Console.ReadLine()); int i = 1; int total = 0; for(i=1; i<num; i++) { if(num % i == 0) total += i; } if(total == num) Console.Write("{0} is a perfect number", num); else Console.Write("{0} is not a perfect number", num); } } }

### Output

Enter a (int) number: 25 25 is not a perfect number

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