If one is the loneliest number that you'll ever do, then six is probably the sexiest.

Heat Vision reports that director D.J. Caruso, apparently not content with leaving the title of Hottest Number Six in Science Fiction History to Tricia Helfer of Battlestar Galactica fame, has hired Teresa Palmer to star as a different Number Six in I Am Number Four, the upcoming sci-fi movie based on the novel by James Frey and Jobie Hughes.

As Number Six, Palmer represents one of nine aliens who escaped their home planet before complete and utter destruction from a rival species. Number Six is hiding out on Earth disguised as a human for her protection.

Palmer joins a growing cast that includes British actor Alex Pettyfer in the title role and the previously announced Sharlto Copley as Number Four's guardian and mentor.