Write a program to find whether entered number is prime or not

Prime Number:

A number which is divisible by 1 and itself is said to be a prime number.

Program:

using System;

namespace ProgrammingQuestion
{
 class Program
 {
   static void Main(string[] args)
   {
     //Variable Declaration
     string checkVal, message;
     int checkNum;
     bool isPrime = true;
     
     //User Input
     Console.Write("Enter Number:");
     checkVal = Console.ReadLine();
     checkNum = Convert.ToInt32(checkVal);
     
     //Prime Logic
     for (int i = 2; i <= checkNum / 2; i++)
     {
       if (checkNum % i == 0)
       {
         isPrime = false;
         break;
       }
     }
     
     //Print Result
     if(isPrime)
     {
       message = $"Entered Number {checkNum} is a prime number.";
     }
     else
     {
       message = $"Entered Number {checkNum} is not a prime number.";
     }
     Console.WriteLine(message);
     Console.Read();
   }
 }
}

Output:

Enter Number:15
Entered Number 15 is not a prime number.