isprime

private boolean isPrime (int number)
{
  if (number<=1) return false;
  if (number==2) return true;
  if (number%2==0) return false;
  int boundary_no=(int)Math.round(Math.sqrt(number));

  for (int i=3; i<= boundary_no; i+=2)
     if (n%i==0)
        return false;

  return true;
}