The other day I got one of my question on the hot question list, it mad it all the way to the top, in fact :)

Does over-reliance on tools imply that you are lazy?

So I got thinking how do these get chosen. I noticed there is a number next to the question in the hot questions tab but I could not figure out what this was. this number seems to be a ranking of some sort as the higher it is the higher up the list but it does not match anything I can see like up votes or views.

This got me thinking is there some kind of vote system like the close system that users can vote for a hot question but I cannot see one so maybe it is for high rep users?