c# - Sum of primes for large numbers -


i've been working on problem time , can't figure out why keep getting overflow error.

the code works fine point doesn't work larger values. have tested , found the breaking point input 225287 (with last non-breaking value being 225286, gives output of 2147431335).

how can work 2,000,000?

class sumofprimes{  static void main(string[] args)     {          primes primes = new primes(2000000);                  console.writeline(primes.list_of_primes.sum());         console.readline();     }    }  class primes {     public hashset<int> all_numbers = new hashset<int>();     public hashset<int> list_of_primes = new hashset<int>();     public hashset<int> list_of_nonprimes = new hashset<int>();       public primes(int n)     {         all_numbers = new hashset<int>(enumerable.range(1, n));         (int = 2; < math.sqrt(n) + 1; i++)         {             (int j = 3; j <= n / i; j++)                 list_of_nonprimes.add(i * j);         }         list_of_primes = new hashset<int>(all_numbers.except(list_of_nonprimes));     }  }

the values have doesn't fit in memory size of int, try using biginteger used on website here.

http://msdn.microsoft.com/en-us/library/system.numerics.biginteger.aspx


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