I have not been an insider at the time, so all my information results from available information, plus interviews I carried out with key stakeholders. As expected, none of these cryptologists liked to be an open book.
Another topic to look at:
The limited total supply of 21 million BTC is almost religiously cited amongst Bitcoin maximalists, and does have some rather straight-forward mathematical explanation. However, it could have easily been shifted to a more catchy number, like a billion BTC or so. Satoshi wrote initially wrote that he considered 42 million BTC, which would have been achieved by an initial coinbase transaction of 100 BTC.
21 - 42 - does that ring a bell?
21 can be obtained from the sum over off the points of the faces of a dice -> cube -> block
21 is also the key number in Blackjack, a casino card game very popular amongst math geniusses - and in March 2008, i.e., a few month prior to the release of teh Bitcoin whitepaper, the movie "21" featuring the Hollywood-adapted story of the notorious "MIT Blackjack Team" was released to US cinemas.
42 - “Answer to the Ultimate Question of Life, The Universe, and Everything”, most tech-nerd "Hitchhikers" likely know what I an talking about.
Under theroretical / idealized (but unrealistic) boundary conditions of a calculation made prior to the launch of the Bitcoin whitepaper and the start of the Bitcoin blockchain, the final mint may be calculated around the year 2142 ...
So maybe the initial and eventual choice of these particular numbers was not as random, and merely mathematically reasoned, as assumed. You find more potential interpretations in the paper.
Note that these points, and other circumstantial evidence dug out in the paper, are certainly of speculative character, but you find more evidence that hints towards a certain propensity of Satoshi Nakamoto for "puns".
So here is the abstract of the preprint entitled "Satoshi Nakamoto and the Origins of Bitcoin – Narratio in Nomine, Datis et Numeris (There is a Story is in the Name, Dates and Numbers)":
The mystery about the ingenious creator of Bitcoin concealing behind the pseudonym Satoshi Nakamoto has been fascinating the global public for more than a decade. Suddenly jumping out of the dark in 2008, this persona hurled the highly disruptive distributed ledger technology “blockchain” that has added the missing native value layer to the internet. Purposely agnostic without advocating any old or fielding new names, this paper first identifies the degrees of freedom Satoshi Nakamoto had available in the design of Bitcoin, and in fabricating snippets of personal data.
By interweaving the substantial collection of previous and new circumstantial with direct evidence, like relevant locations and happenings in history and at the time, a consistent skeleton of Satoshi Nakamoto’s biography transpires. The results underpin that the iconic creator of Bitcoin most likely encoded bits of information in his self-chosen alias, dates and blockchain parameters, which particularly point to the numbers 21 and 42, and the numeral systems used in Bitcoin’s framework.
Moreover, a psychogram of a reclusive and capricious genius is drawn, which sheds new light on Satoshi Nakamoto’s background, mindset, pastimes, and penchant for puns; this study may also explain the motivation of his abrupt departure from the online community, his continuing abstinence from engaging with the Bitcoin community, and from reaping the fruits of his mindboggling wealth. From a history of science and technology perspective, such an altruistic sacrifice for the benefit of his brainchild is entirely unprecedented.
Note: For getting a better grip on the (unavoidably) large document systematically gathering the comprehensive pool of existing and new circumstantial evidence, you might use the bookmarks panel in teh PDF file.