Unfortunately, TC has removed the feature where I can find out exactly how many ranked competitors there are - they remove people who haven't competed recently. It sounds more impressive if I can type in a larger number.
Fortunately, I just got a data dump from the admins, containing the name/ranking/number of competeitions/last competition of everyone in Topcoder. So I write a quick parser to tell me how many items are in it.
"Currently ranked #6 out of over 7000 ranked competitors"
I feel kinda sleazy, but it's *true*!