It's not really a thing that's being kept track of.
It's easy to find downloadable lists of primes smaller than a few billion (e.g. at https://primes.utm.edu/lists/small/).
But if you go a few orders of magnitude above that -- say, if you want a list of all primes up to a trillion -- storing and distributing the lists themselves begin to be more tedious and expensive than just recomputing the primes when you need them. There are 37,607,912,018 primes less than a trillion; storing all of them would fill a medium-sized hard disk. And what for? Most of the things you could do with a table of such primes, such as looking up a number to see if it's prime, can be done with less resources simply by testing it for primality from scratch. (Testing whether a 12-digit number is prime is quick and simple if you have a computer, and if you don't have a computer how would you even store or access a table with 37 billion entries?).
So, depending on what you mean by "known", the number you're looking for probably changes from day to day, as someone somewhere computes a longer list of primes than anyone else was keeping yesterday, or deletes their list again to use their disk space for something more productive.