Big Primes!

Dr. Jablonski let us know that the Great Internet Mersenne Prime Search (GIMPS) project has just announced the discovery of the largest known prime number.  Remember, a Marsenne Prime is a prime number which can be written as 2^{n}-1.  The GIMPS is a group of volunteers (you too can be one!) who test numbers of that form looking for larger and larger primes.  Mostly for fun, but the Electronic Frontier Foundation (EFF), is offering a $150,000 prize for the first prime with 100 million digits and $250,000 for the first prime with 1 billion digits!  Here’s a link to their prize page.

In case you want to check it at home, it is


But we should warn you that it has no less than 17,425,170 digits.  To see the whole number click here.  To get an idea of how big that number is (and to disabuse you of the notion that you’ll print it out in the computer lab), if you were to print it out in 12 point font on standard 8 1/2 by 11 sheets of paper, it would run to 5,000 pages!

We also have some “middle America” pride that this Mersenne Prime was found by Dr. Curtis Cooper,  a professor at the University of Central Missouri.  It should be noted that you don’t need to be a professor to be a part of the GIMPS project, all you need is a computer!

The Internet being interested in all things, the new prime was discussed on MetaFilter.  A discussion perhaps best summed up (and definitely won by) by jimmythefish’s wry comment:

I can appreciate this, and I was once again mind-boggled the other day when looking at a comparative illustration between planets in our solar system and the largest stars. I am reminded that my brain is very weak.

This should not come as a surprise, however, because if you hand me a calculator I will probably spell BOOBS with it instead of doing any actual work.

— jimmythefish