Largest Known Prime Number Discovered. (Article)

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Article here. A math professor has discovered a prime number whose digits number 17,425,170. That is seventeen-million-four hundred-twenty five-thousand-one hundred-seventy digits long. This dethrones the previous record of a prime number that is ~12 million. The number in question is 2^57,885,161-1.

From the article " the number is the 48th example of a rare class of primes called
Mersenne Primes. Mersenne primes take the form of 2 raised to the power
of a prime number minus 1. Since they were first described by French
monk Marin Mersenne 350 years ago, only 48 of these elusive numbers have
been found, including the most recent discovery."

[earmuffs]

People have to much time on their hands.

[earmuffs]

Wait, if the equation is 2^a prime number minus 1 then 2^57885167 -1 is bigger then his number.
Where's my $3,000?

[devilsadvoc8]

Forgive what may be an ignorant question, but other than the pursuit of knowledge, what does knowing if that number is prime or not do for us? I am not saying that people shouldn't look for them. Just an innocent question.

[nach_in]

(06-02-2013 03:47 PM)devilsadvoc8 Wrote:  Forgive what may be an ignorant question, but other than the pursuit of knowledge, what does knowing if that number is prime or not do for us? I am not saying that people shouldn't look for them. Just an innocent question.

Prime numbers are used a lot in cyber-security, the bigger the number the harder to crack the codes, because there's no formula that provides prime numbers every single one of them must be calculated individually (there're a few candidates for the formula but they're not proven yet). That's why this stuff can be a big deal.

[BryanS]

(06-02-2013 03:42 PM)earmuffs Wrote:  Wait, if the equation is 2^a prime number minus 1 then 2^57885167 -1 is bigger then his number.
Where's my $3,000?

Prove that 2^57885167 -1 is prime. 2^4 -1 is not prime, so the generic formula 2^a -1 for some value of a does not necessarily make a prime number.

[Chas]

(06-02-2013 11:09 PM)BryanS Wrote:  

(06-02-2013 03:42 PM)earmuffs Wrote:  Wait, if the equation is 2^a prime number minus 1 then 2^57885167 -1 is bigger then his number.
Where's my $3,000?

Prove that 2^57885167 -1 is prime. 2^4 -1 is not prime, so the generic formula 2^a -1 for some value of a does not necessarily make a prime number.

4 is not prime. The exponent needs to be a prime number.

[Free Thought]

Well...

Peaking in this thread was a mistake.

I am thoroughly confused.

[Phaedrus]

I tried to calculate 2^57,885,161 -1 on my computer. At around 2^6,500,000 I ran out of memory.


I had to do it iteratively, since using Python's built-in exponentiation function just results in the interpreter locking up and crashing.

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(07-02-2013 03:51 AM)Phaedrus Wrote:  I tried to calculate 2^57,885,161 -1 on my computer. At around 2^6,500,000 I ran out of memory.


I had to do it iteratively, since using Python's built-in exponentiation function just results in the interpreter locking up and crashing.

Dude, you expected different results?