Problem 10. Summation of primes

public class euler10 {
    public static void main(String[] args) {
        int N = 2000000;
        long sum = 0;
        for (int i = 1; i < N; i++) {
            if (isPrime(i)) {
                sum += i;
            }
        }
        System.out.println(sum);
    }
    public static boolean isPrime(long n) {
        if (n <= 1) return false;
        long i = 2;
        while (i*i <= n) {
            if (n % i == 0)
                return false;
            i++;
        }
        return true;
    }
}