//Algorithm to check if a number is Prime or not? 

//This C# Program Checks Whether the Given Number is a Prime number if so then Display its Largest Facor. 

//Here first the number that is obtained is checked whether the number is prime or not and then the largest factor of it is displayed.

​

//A prime number (or a prime) is a natural number greater than 1 that has no positive divisors other than 1 and itself.

​

using System;

public class Program

{

    public static void Main()

    {

        Console.Write("Enter a Number : ");

            int number, count=0;

            number = Convert.ToInt32(Console.ReadLine());

            for(int i = number-1; i>1; i--){

                if (number%i ==0){

                    count ++;

                }

            }

        if (count >1){

            Console.Write("It is not a Prime number : ");

        }

        else{

            Console.Write("It is a Prime number : ");

        }

    }

}