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New Largest Prime Found: Over 7 Million Digits

Posted by timothy on from the tim-adds-2-and-takes-credit-for-the-next-one dept.

Jeff Gilchrist writes "On May 15, 2004, Josh Findley discovered the 41st known Mersenne Prime, 2 to the 24,036,583th power minus 1. The number is nearly a million digits larger than our last find and is now the largest known prime number! Josh's calculation took just over two weeks on his 2.4 GHz Pentium 4 computer. The new prime was verified by Tony Reix in just 5 days using only half the power of a Bull NovaScale 5000 HPC running Linux on 16 Itanium II 1.3 GHz CPUs. A second verification was completed by Jeff Gilchrist of Elytra Enterprises Inc. in Ottawa, Canada using eleven days of time on a HP rx5670 quad Itanium II 1.5 GHz CPU server at SHARCNET. Both verifications used Guillermo Ballester Valor's Glucas program." Read on for more on the discovery, including how you can help find more primes.

Gilchrist continues "If you want to see the number in written in decimal, Perfectly Scientific, Dr. Crandall's company which developed the FFT algorithm used by GIMPS, makes a poster you can order containing the entire number. It is kind of pricey because accurately printing an over-sized poster in 1-point font is not easy! Makes a cool present for the serious math nut in your family.

For more information, the press release is available.

Congratulations to Josh and every GIMPS contributor for their part in this remarkable find. You can download the client for your chance at finding the next world record prime! A forum for newcomers is available to answer any questions you may have.

GIMPS is closing in on the $100,000 Electronic Frontier Foundation award for the first 10-million-digit prime. The new prime is 72% of the size needed, however an award-winning prime could be mere weeks or as much as few years away - that's the fun of math discoveries, said GIMPS founder George Woltman. The GIMPS participant who discovers the prime will receive $50,000. Charity will get $25,000. The rest will be used primarily to fund more prime discoveries. In May 2000, a previous participant won the foundation's $50,000 award for discovering the first million-digit prime."

16 of 305 comments (clear)

  1. I hate to be a pushover... by Capt'n+Hector · · Score: 4, Interesting

    ... but why exactly is this so important? Can we use this number in any way, or is it just another prime?

    --
    Quid festinatio swallonis est aetherfuga inonusti?
    Africus aut Europaeus?
    1. Re:I hate to be a pushover... by barcodez · · Score: 5, Interesting

      Well we can make a perfect number with it.

      Every Mersenne prime gives rise to a perfect number.

      To answer your question a little more seriously the number is not much use in itself but like many peices of research the route to the goal often turns out more interesting information than the goal. GIMPS pushes back the bounds on many levels such as highly optimised coding and mathematical DC.

      --

      ----
    2. Re:I hate to be a pushover... by vrmlguy · · Score: 2, Interesting

      Well, you can use it to make a *really* big RSA encryption key.

      --
      Nothing for 6-digit uids?
    3. Re:I hate to be a pushover... by eidechse · · Score: 3, Interesting

      Binary math was once thought to be a useless curiousity.

    4. Re:I hate to be a pushover... by SamSim · · Score: 1, Interesting

      I consider it an extremely good way to attempt to impress chicks, since chicks who are impressed by this kind of thing are more likely to be chicks.

      --
      qntm.org
  2. Distributed Computing? by drskrud · · Score: 3, Interesting

    Does anyone know if a distributed computing project exists for finding large prime numbers? That would be a pretty cool way to spend some CPU cylces.

    1. Re:Distributed Computing? by Anonymous Coward · · Score: 2, Interesting

      GIMPS

  3. Re:In case you missed it by Anonymous Coward · · Score: 1, Interesting
    I think I might have a faint idea why. Let's see... do i want to use my spare CPU power to:
    • Search for intelligent aliens?
    • Find a cure for cancer?
    or
    • Calculate a really fucking big, really fucking useless number?
  4. The real question by panxerox · · Score: 1, Interesting

    is this number now copyrighted?

    --
    "It's so convenient to have a system where everyone is a criminal" - A. Hitler
  5. As a corollary, by kevinatilusa · · Score: 4, Interesting

    He's also found the largest known perfect number, 2^(24,036,583-1)*((2^24,036,583)-1)

  6. Picture Frame by KhalidBoussouara · · Score: 3, Interesting

    I understand that producing such a poster will be expensive but this is ridiculous:

    Without frame: $77.00
    With frame: $247.00

    SCO's claim that their code has been stolen sounds more logical than this!

  7. Last digit is a 7 by product+byproduct · · Score: 4, Interesting

    Actually the last 9 digits are 733969407, as this simple C program will show you:

    #include <stdio.h>

    int main()
    {
    int i;
    int p = 1;
    int m = 1000000000;
    for (i = 0; i < 24036583; i++)
    p = p*2 % m;
    p = (p+m-1) % m; // minus 1
    printf("%d\n", p);
    }

  8. What if by vijaya_chandra · · Score: 2, Interesting

    What if the message that your SETI's going to find out happens to contains this prime!?!?

    Isn't it possible that some civilisation is so advanced that their 'bc' would give back the 50th mersenne prime just like our bc would return 3*5

    Wouldn't it be cool to find out that the msg you've just now found on SETI isn't gibberish but a hi from another advanced civilisation

  9. OMG again by vijaya_chandra · · Score: 1, Interesting

    Offtopic!?!?!
    Am I seeing things

    Who ever the hell moderated the parent needs some medication.
    This AC was replying to one who didn't RTFA, and gets modded down by another who definitely RTFA.

    (Karma be damned : I am no better than an AC now anyway)

  10. Re:Legit uses for Mersenne Primes by Anonymous Coward · · Score: 2, Interesting
    It's gonna be a little obvious to crackers when I use two mersenne primes to help create my public and private keys.

    Don't use one that's based on factoring, then. Go for a discrete-logarithm based cryptosystem, like ElGamal. Mmmm... 23-megabit asymmetric key... (Now we just need a 3-megabit hash function to make the signatures worthwhile. Oh, and some serious silicon to push the electrons required for a digital signature with a key that size. Ooog.)

  11. A slightly different challenge by Anonymous Coward · · Score: 1, Interesting

    One thing I'd like to know is, what is the smallest unknown prime number? And more importantly, is there an award for finding it, thereby making it no longer unknown?