Wouldn’t it be the 21millionth?
The 18.4 millionth Bitcoin is due to be mined around 2140. Once this is done, there will be no more new Bitcoin, with the entire supply permanently capped at 21 million. This raises many questions about the future of Bitcoin and its effects on global finance
https://thebitcoinstreetjournal.com/the-last-bitcoin-what-will-happen-once-all-btc-are-mined/
Discussion
I plan on living until 2140 so I hope to see you then!