I know it's suppose to be in the millions but does anyone know a more exact figure?

A total of 7,450,765 souls. Fourteen more on the way with the first to be expected somewhere late July. And that's what we know of.

...

But, no. No clue, actually. Just puling your leg there. I was wondering about this sort of thing as well, with regards to sustainability of any mass of people in a hostile environment totally dependable on artificial circumstances for even the most basic needs to survive. As such, I would second the question.

(As a GM, I would probably just pick a number that 'feels' right, and go with that. Nothing like a good old GM Gut Feeling Guesstimate.)

BTW, this is not an unreasonable guess, given the population of Earth for this time period. In fact, it could be much higher, at least as many as are elsewhere in the Sol System.