So Big, It's Like The Biggest (Prime) Number Ever

One of the sessions I deliver is about modern cryptographic algorithms, specifically looking at RSA. This involves looking at prime numbers, and generally speaking, the bigger they are, the better. On the penultimate slide (written in May 2017) I show the biggest Prime known as of that date. It's

 

I tell people that I've written it in that format because it's far too long to write down as a "normal" number as it has 22,388,618 digits, but somebody - Matt Parker, no less - has actually gone and had it printed. You can see that in the Numberphile video below:

 

As far as I'm aware this is still the largest prime known to humanity.