yeah, now feels like things are starting to make a bit more sense 
idk, for some reason i just didn’t see that i do not actually need to compute this largest of known prime numbers in the first place! 
… since… well since it is basically given as a power of 2, therefore i do already have the log2 of it in hand!
so:
log919(2^82589933 − 1) = ( for all practical intents and purposes ) log919(2^82589933) = log2(2^82589933) / log2(919) = 82589933 / log2(919) = 8389942.6427…
now seams to me that i can take away a couple of things from this:
- really good refresher on how log works
- explored some libs for dealing with huge numbers
- got reminded that some / often times i am a bit of a doofus
- got reminded that asking for help ( although slightly unpleasant / embarrassing ) is, more often than not, by far the smartest course of action!