Layah is absolutely correct about U.S. house numbers. I once lived in a house with the number "10511" and the street was only a single block long.

But the reason for assigning such large numbers is simple. It's harder to remember large numbers than small ones. And any governmental bureaucracy is going to jump at the chance to make our lives a bit harder, if only to the extent of making us memorize one or two extra digits in street addresses.