Prime using While

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication14
{
    class Program
    {
        static void Main(string[] args)
        {
            int primeInQuestion = int.Parse(Console.ReadLine());
            int i = primeInQuestion - 1;
            while (primeInQuestion%i != 0 && i>1 && primeInQuestion != 2 && primeInQuestion !=3)
            {
                i--;
                if (i < 3 && primeInQuestion % i != 0  )
                    Console.WriteLine(primeInQuestion + " is prime.");
            }
            if(primeInQuestion == 2 || primeInQuestion == 3)
                Console.WriteLine(primeInQuestion + " is prime.");
            if (i>1 && primeInQuestion%i ==0 && primeInQuestion > 3)
                Console.WriteLine(primeInQuestion + " isn't prime.");
        }
    }
}

/* Fibonacci:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication14
{
    class Program
    {
        static void Main(string[] args)
        {
            int a1 = 0;
            int a2 = 1;
            Console.Write("Amount of numbers you'd like to be calculated: ");
            int amount = int.Parse(Console.ReadLine());
            Console.WriteLine(a1 + "\n" + a2);
            int i = 0;
            while (i < (amount-2))
            {
                i++;
                int a3 = a1 + a2;
                Console.WriteLine(a3);
                a1 = a2;
                a2 = a3;
            }
        }
    }
}
*/

/* Triangle:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication14
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Enter lenght:");
            int lenght = int.Parse(Console.ReadLine());
            int i = 0;
            while (i < lenght)
            {
                i++;
                int b = i;
                while (b > 0)
                {
                    b--;
                    Console.Write("*");
                }
                Console.WriteLine();
            }
        }
    }
}

*/