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Factors of a very large whole number

  • 25-11-2005 12:26PM
    #1
    Registered Users, Registered Users 2 Posts: 7,499 ✭✭✭


    Does anybody know how to find the factors of a verry large whole number? The "Sieve of Eratosthenes" is too slow....
    Thanks
    (PS I have to be able to do this on paper, no computers can be used)


Comments

  • Registered Users, Registered Users 2, Paid Member Posts: 16,307 ✭✭✭✭Pherekydes


    Cryptography challenge?

    Factoring the numbers is the easiest part.

    Raising something to the power of a (possibly) six digit number is the bitch!:p


  • Registered Users, Registered Users 2 Posts: 7,499 ✭✭✭fletch


    Yeh was a Cyptology challenge....turns out it was Fermats Theorem...(I know where not to come when I need some maths problem solved quickly!) :D


  • Registered Users, Registered Users 2, Paid Member Posts: 16,307 ✭✭✭✭Pherekydes


    I know what you're going through. I went through the same this time last year.

    P.S. Of course, I have the two €50 checks to show for it.:D

    P.P.S. Well I don't anymore. One went to the charity and I spent the other.;)


  • Banned (with Prison Access) Posts: 1,081 ✭✭✭jcf


    Slow coach wrote:
    Cryptography challenge?

    Factoring the numbers is the easiest part.

    Raising something to the power of a (possibly) six digit number is the bitch!:p


    I think you have that the wrong way there, its factoring large numbers thats
    a bitch and multiplying/raising to powers thats easier (although a 6 digit index is difficult, factoring the result would be far far more difficult)


  • Registered Users, Registered Users 2, Paid Member Posts: 16,307 ✭✭✭✭Pherekydes


    jcf wrote:
    I think you have that the wrong way there, its factoring large numbers thats
    a bitch and multiplying/raising to powers thats easier (although a 6 digit index is difficult, factoring the result would be far far more difficult)

    OK. I found it (dead) easy to factor the 7 digit numbers.

    And I found it hard doing the other stuff.


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  • Banned (with Prison Access) Posts: 1,081 ✭✭✭jcf


    Sorry i thought you were talking about factoring 100+ digit numbers


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