The largest known prime as of 11/18/23 is 2^82,589,933 − 1. This record was set in December 2018.

For the purposes of this question, in order for a number to qualify as a "known" prime, there must be a known closed form expression for this number involving only integers and the operations [+, -, *, /, ^] that uses at most 1000 characters to express. Reputable sources must agree by 12/31/2024 that the number has been proven to be prime, and proofs assisted by computer computations are, of course, allowed.