I did some math on this, extrapolating from the deaths number. The trick is that you have to assume a true mortality rate, which is one thing that really is not known and won't be for a while yet.
If you assume 14 day lag time from contracting to dying, and assume mortality rates from 0.5% to 1.5%; then it works out that the actual infected compared with confirmed cases is somewhere between 3x and 8x. So confirmed atm is about 340k, so figure between 1-2M in reality.
It's out there in the wild, and it's not going to be eliminated like polio. In the end, there are only 2 things that will really stop this. Herd immunity once ~60% of people have had it, or a treatment that helps enough to reduce the mortality rate by an order of magnitude (or two).