Optimus Primed

Do you know what a prime number is?  Think waaay back to those good ol’ days in middle and high school.

A Prime Number is a number that only has two factors: 1 and itself.  Numbers like 2, 3, 5, 7, 11 and 13 are prime numbers.  Of course you could divide any of these numbers by anything on your calculator, but the only factors that give you an integer value (no decimals or fractions) will be 1 and the number.

So far, there isn’t a technique or forumla to find a prime number besides guess and check.  Recently the largest prime number was found.  Take a stab at how many digits there might be.  Just try and guess.

What did you get to?  Like, a million?  Try 13 times that.  That’s right.  Thirteen million digits.  And you thought a bajillion was a big number.

Interestingly enough, there are still prizes up for grabs.  The two big fish still left to be caught are the 100-million digit prize ($150,000) and the 1-billion digit prize ($250,000).

Want to try it out for yourself?  The Great Internet Mersenne Prime Search (or simply GIMPS) is always looking for idle CPUs.  By downloading the software, you can let your computer do a little computing while the CPU would otherwise be idling.

A Mersenne Prime is a prime number of the form (2^n) - 1.  This latest one found is (2^43,112,609) - 1. (’^’ means ‘to the power of’).

Just don’t get your hopes up of making 150 g’s in an afternoon for doing nothing.  For an ordinary desktop computer to test a 100-million digit number, it would take about four years; for a 1-billion digit number, 500 years.  I think we might need a new algorithm.