I think there's a word for a google search returning only one hit, but I can't remember what it is. (Googlewhacking is I think finding pairs of words to return one hit.)
Tom Kelsey and I once tried (not very hard) to find the smallest number (I mean positive integer) which has no hits in Google. Of course if we posted it here it would get a hit. But the interesting thing is that the number (whatever it is) is surprisingly large. Try it yourself. Of course your expectation may be more accurate so you won't be surprised.