What is the best way to determine if 91042014201224789 is prime?
Now suppose you are stuck on an island with nothing but a slide rule, any one specific table of your choosing, and an abacus, what is the best way to "by hand" determine if 91042014201224789 is prime?
SPOILER ALERT:
91042014201224789 is a product of two primes, both of which are upwards of 1.6 Million.
If you were stuck on a deserted island with aforementioned tools, how would you best go about factoring 91042014201224789? The naive, yet easy to implement on a computer/abacus/etc., way is to literally check the remainder when you divide 91042014201224789 by 2, then 3, then 4, then 5, ad infinitum, and see if you can hunt down the smallest factor of 91042014201224789.
As it turns out, if we were to attempt to divide 91042014201224789 by 2, 3, 4, etc., to check for even divisibility (i.e., no remainder), we would have to check every number less than (???).
Or, the TL;DR version: factor 91042014201224789 by hand or prove it is prime.
