If you enter exactly the same search terms on Google that I do at the same time, then we would both receive the same results.
If you search for Richard Dale (no quotes) in Google, then the first entry in the search results that refers to me is eighth on the list. Hence my Google number is 8. As it happens, this entry is for my board bio on the Hazon website. My brother, Andy Dale, has a Google number of 1, as does my wife.
Obviously a mixture of an unusual name and/or fame will improve your Google number (improvement means moving closer to, or getting to, 1).
I am flattered that it is Hazon that has brought my Google number into single digits. Previously my Google number was not economically computable (I didn't show up for pages and pages). Maybe this blog, over time, will improve my number even more. I am not holding my breath!
If you use the new Google Personalized Search this will distort the numbers (by making the search results dependent on your own search history, rather than purely on the Google page rank algorithm). If you use the Personalized Search service, I assume that logging out from your account normalizes the results again.
What's your Google number?
PS: as I prepare this post, I googled "google number" and found an alternate version dating back a few years: seeing the number of hits against your name (in quotes) that Google returns. This seems unsatisfactory to me, since many of the hits may have nothing to do with you (as in my own case).
PPS: I also just checked my Yahoo! Search number - it is unknown (but greater than 100). Clearly Google is a superior search engine!