That’s a cool number, because it’s 29. In hex, it’s 200 (traditionally written 0x200, or 200H for old-school 8080 assembly programmers). Inn octal it’s 1000 (or, traditionally, 01000). In binary it’s 100000.
(After I noticed that, I was of a mind to wait until 01-10-10 to publish it.)
Update: it’s actually not number 512. WordPress is counting something (edits? comments?) rather than individual postings?