Code Not Running For Large Numbers (Unhandled Exception error)

Question

Code below works for stated number (6008514751), but throws up error for the desired Max value: 600851475143. I've used type long in place of 'int', so I don't see why my program is not able to run 600851475143. I would greatly appreciate any help.

Error thrown is: Unhandled Exception:
System.OverflowException: Arithmetic operation resulted in an overflow.
at HelloWorld.MakeSieve (System.Int64 max) [0x00000] in <0273ea83c32446be9aa2f9fc5d30dab0>:0
at HelloWorld.Main () [0x00000] in <0273ea83c32446be9aa2f9fc5d30dab0>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.OverflowException: Arithmetic operation resulted in an overflow.
at HelloWorld.MakeSieve (System.Int64 max) [0x00000] in <0273ea83c32446be9aa2f9fc5d30dab0>:0
at HelloWorld.Main () [0x00000] in <0273ea83c32446be9aa2f9fc5d30dab0>:0

*Update 1: Some of you suggested I take a look at "I need very big array length(size) in C#". I tried replacing my list with type double (even tried replacing all 'long' with 'double), to no avail.

Update 2: A trailing L (Max = 600851475143L) not helping much.

Thank you!

using System;
using System.Collections.Generic;

class HelloWorld
{

    public static long Max = 600851475;
    public static List<long> AllPrimesBelowMax = new List<long>();
    public static long maxPrime = 0;

    static void Main()
    {
        MakeSieve(Max);
    }

    private static bool[] MakeSieve(long max)
    {
        bool[] isPrime = new bool[max + 1];
        for (long i = 2; i <= max; i++)
        {
            isPrime[i] = true;
        }

        //cross out multiples
        for (long i = 2; i <= max; i++)
        {
            //check if i is prime
            if (isPrime[i] == true)
            {
                //cross out multiples of i
                for (long j = i * 2; j <= max; j += i)
                {
                    isPrime[j] = false;
                }
            }
        }

        for (long i = 2; i <= max; i++)
        {
            if (isPrime[i] == true)
            {
                AllPrimesBelowMax.Add(i);
            }
        }

        Console.WriteLine(AllPrimesBelowMax[AllPrimesBelowMax.Count - 1]);

        return isPrime;
    }
}