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New Largest Prime Found: Over 7 Million Digits

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."

13 of 305 comments (clear)

  1. harrumph by maxbang · · Score: 5, Funny

    Say all you will, but Optimus is still the ultimate prime.

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    I also reply below your current threshold.
  2. 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.

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  3. Re:I hate to be a pushover... by irokitt · · Score: 5, Funny
    This is of course an attempt to impress chicks.

    Hey baby, did you know I discovered the longest prime number?


    Notice I said it's an attempt, I didn't say it would work;)
    --
    If my answers frighten you, stop asking scary questions.
  4. Hey, this is very important....... by Lexomatic · · Score: 5, Funny

    Who knows, one day you might find yourself struck in the tiger den with multiple doors all marked with Mersenne Primes, and a sign saying, "safe exit thru the door marked with the 41st Mersenne Prime". Yeah, then who is gonna bitch about not memorizing that sucker, huh?

  5. I knew it by jmoen · · Score: 5, Funny

    Size does matter :)

  6. Here is the whole number! by fredrikj · · Score: 5, Funny

    In binary: 11111111111111111111111111111111111111111111111111 11111111111111111111111111111111111111111111111111 11111111111111111111111111111111111111...

    Your comment violated the "postercomment" compression filter. Try less whitespace and/or less repetition. Comment aborted.

    Sorry :/

  7. fermat was here by werdnapk · · Score: 5, Funny

    I have discovered a truly marvelous demonstration of a 10 million digit prime which this margin is too narrow to contain.

  8. Re:I hate to be a pushover... by shigelojoe · · Score: 5, Funny

    Which is why I'd hate to be a math student in the 22nd century:

    Teacher: Ok class, your homework for tomorrow is to find a Mersenne prime longer than 1,000,000 digits. *By hand*. I don't want to see any computer printouts.

    Class: *Groan*

  9. Re:Not in this case... by Anonymous Coward · · Score: 5, Insightful
    since 2^(odd number)+1 is always a multiple of 3

    Theorem For any positive odd integer n, 3 divides 2^n+1

    Proof We will use the Principal of Mathematical Induction.

    Basis When n=1, we have 2^n+1=2^1+1=3. Furthermore, when n=3, we have 2^n+1=2^3+1=9.

    Induction Now suppose n is a positive odd integer, and that 3 divides 2^n+1. We will now show that 3 divides 2^(n+2)+1.

    Since 3 divides 2^n+1, there exists an integer q such that 2^n+1=3*q

    2^(n+2)+1=2^(n+2)+4-3
    =2^2*2^n+4-3
    =4*(2^n+1)-3
    =4*3*q-3
    =3*(4*q-1)
    =3*r, r=4*q-1

    Where r is an integer by the closure properties of multiplication and subtraction.

    QED

  10. Re:I hate to be a pushover... by Paradise+Pete · · Score: 5, Funny
    I have pi tattooed on my dick. It usually says 3.14, but man when it gets angry, it goes all the way to 3.141!

    Wait, I didn't tell that right.

  11. Re:Not in this case... by chgros · · Score: 5, Insightful

    More directly (without induction):
    if T = 2^(2p+1) + 1:
    T = 2^(2p+1) - 2 [mod 3]
    T = 2(2^2p - 1) [3]
    T = 2(4^p - 1) [3]
    T = 2(1^p - 1) [3]
    T = 0 [3]
    qed

  12. Re:I hate to be a pushover... by WalksOnDirt · · Score: 5, Informative

    "Are Mersennes really the easiest numbers to prove prime?"

    Yes, because of the Lucas Lehmer primality test, which you can google if you want to see the details.

    The standard proof of primality involves factoring the number one less than or one greater than the prime. Obviously, the number one greater than 2^p-1 is easily factored, which is the basis of the test.

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    a,e,i,o,u and sometimes w and y (at be if of up cwm by)
  13. Want a simple proof? by product+byproduct · · Score: 5, Insightful

    2^(odd number)+1
    = (-1)^(odd number)+1 [mod 3]
    = -1 + 1 [mod 3]
    = 0 [mod 3]