从.php编辑.text的chmod是什么

I've a test.txt file on same folder of myphp.php, test.txt is empty, myphp.php have this:

      <?php
        $g = fopen("test.txt", "w+");
        fwrite($g, 'some text here');
        fclose($g);

When I type www.mysite.com/myphp.php it will only work if I have public permission to "write" (ex 666) on the test.txt but I want it to work with 664, is it possible?