less than quarter mil number, that's very very early on! mine is over 3.8 million, and I created it relatively early on considering I was living in Europe :)
I think I remember my number because back then when you had to reinstall software or put it on new machine you always went by your number, instead of your email or username. That's why I think I still remember it :)
Don't ask me how I remember this number that I haven't used in 20-odd years, but maybe that alludes to the impact it made on the community at large.
RIP ICQ