Star Trek Discovery: Every Easter Egg & Hidden Reference From 'People Of Earth'
13. The Answer To Life, The Universe, And Etc.
In the aforementioned flashback to Michael's missing year, the artifact that she trades for is old Starfleet tech bearing a starship registry: NCC-4774 (plus possibly some more numbers we can't see).
This is one of the less subtle references to 47, the magic number that was frequently referenced in the Star Trek: The Next Generation-era of the franchise. 47 has been widely documented as what Rick Berman called "the answer to life, the universe, and everything" adjusted for inflation.
Even Memory-Alpha (the Star Trek wiki) hasn't catalogued all the references to 47 across the decades, but here's a link to the ones they've caught so far.