I was just having a read through some of the recently released email history between Satoshi and Martii 'Sirius' Malmi. I only just became aware of these, so thought I'd share in case others had missed/are interested:

https://twitter.com/pete_rizzo_/status/1761040089075888292

One question I've always had is why he picked 21 million? Why not a round number, like 50m or 100m? And why is a Satoshi 100 millionth of a BTC and not a 10 millionth or a 1,000 millionth? Did he make assumptions about future value and therefore the minimum required 'value' of a satoshi relative to fiat?

Curious.