2, raised to the 20,996,011, minus 1.

That number is unlikely to ring a bell:

A 26-year-old graduate student in the US has made mathematical history by discovering the largest known prime number.

The new number is 6,320,430 digits long. It took just over two years to find using a distributed network of more than 200,000 computers.

Prime numbers are positive integers that can only be divided by themselves and one. Mersenne primes are an especially rare type of prime that take the form 2 p-1, where p is also a prime number. The new number can be represented as 2 raised to the 20,996,011, minus 1 [I have changed the presentation here, in lieu of upper case power notation]. It is only the 40th Mersenne prime to have ever been found.

Here is the full story, from NewScientist.com. George Woltman adds: “There are more primes out there.”

The saga is also an account of the voluntary private production of public goods, given the large number of computers whose “spare processing power” was donated toward this end. If you want to contribute toward this sort of endeavor, sign up here.