I'm confused by your "10 to the 5th" references. That'd be 100,000, which number I don't think I used anywhere.... To count the number of eight-digit radars, you take 10*10*10*10*1*1*1*1, because each of the first four digits can be anything, while each of the last four digits must match the corresponding digit from the first half. So the number of radars is 10 to the 4th, or 10,000. And, yes, the same goes for repeaters.
No...not that I'm entirely sure I'd notice if I had. I remember once running across someone who had a standing offer of like $100 for a note with the first eight digits of pi, but I don't know if he ever found it.... Personally, I'd like an 09699690. I think it's nifty that this number is interesting both from a collecting perspective (it's a radar) and from a mathematical perspective (it's...well, you figure it out ).
Yeah, I figured that out later, I was just too lazy to make a third EDIT and say it. But sure, that's all there is to it...