Last month, researchers found the 43rd Mersenne Prime: 230,402,457-1. It’s 9,152,052 decimal digits long.

This is a great use of massively parallel computing:

The 700 campus computers are part of an international grid called PrimeNet, consisting of 70,000 networked computers in virtually every time zone of the world. PrimeNet organizes the parallel number crunching to create a virtual supercomputer running 24×7 at 18 trillion calculations per second, or ‘teraflops.’ This greatly accelerates the search. This prime, found in just 10 months, would have taken 4,500 years on a single PC.