I think there probably aren't any numbers that are inherently lucky or unlucky (but who knows?), but I believe numbers can probably be lucky or unlucky if you believe they are. Also, believing a certain numbers are auspicious or portentous seems to create a "protocol" between you and the universe, or maybe angels or guides or something, where you're shown those numbers to help guide your decisions.

Aaron's answer that the concept of lucky numbers is pseudoscience bugs me, because it's so scientistic. Pseudoscience doesn't or shouldn't refer to anything that's not scientific. The root "pseudo" basically means that something is pretending to be something else, so pseudoscience should refer to ideas that purport to be scientistic but use specious scientific reasoning or evidence. Calling everything that's not science pseudoscience is like calling anything that's not leather faux leather, and it reflects the scientistic ideology that the only valid way to come to any conclusion or know anything is through science.