TITLE: What is the largest $n$ for which the $n$th prime is known?
QUESTION [11 upvotes]: $p = 2^{43,112,609} - 1$ is currently the largest known prime, but the $n$ for which this $p$ is the $n$th prime is, presumably, unknown.  What is the largest $n$ for which the $n$th prime is known?  (For the sake of definiteness, let's say a number is "known" iff all of its decimal digits have been computed.)

REPLY [4 votes]: update 2014:
$\begin{align}π(10^{26}) = 1699246750872437141327603\\
π(2^{89})= 1320486952377516565496055\end{align}$
Both culled from OEIS, http://oeis.org/A006880, http://oeis.org/A007053. A likely source for reasonably up to date info on this kind of thing.