I'm not sure if there is a max number. If not then after several years the number would be beyond reason. Even if it got to one satoshi, but continued to have support there. 500 of these coins would get you over 1000 BTC...theoretically
This question is on many people's minds. However, with widespread adoption the total number of coins is not that big a thing. At some point in future if (when widely adopted) and it does become a huge problem for some reason, it can be sorted then with an adjustment to the staking parameters.
You can ask a similar question - how many fiat dollars are there in total out there in the money supply?
I have left it very easy to modify this later if needed. We can also raise fees, add stake modifiers, or do it a new way. Many options in the future
As far as the max...how high can you count?
Looking into this with more detail. It's not about how high one can count. having just 1 coin staking as you desire will get to this in 5 years:
8.2634497615169870410629960038999 e+191
If I am wrong I would love for someone to show me, but the numbers will start getting to extreme. Is that what you trying to test?
Edit: 1 coin per block is just too much. To lengthen time on this, 10 '10k-toshis' might be a more feasible block value...again theoretically. But not my coin and I can't complain as I'm doing well.