20180510, 06:55  #1 
May 2018
1 Posts 
how much time does it need to factor a number of 289 digits?
It has taken me 5 days to factor a 289 digits number,I WANT TO KNOW how much time does it need to factor a number of 289 digits?

20180510, 10:52  #2  
Bamboozled!
"πΊππ·π·π"
May 2003
Down not across
24626_{8} Posts 
Quote:
The answer to your question is that the time is between negligible (for instance if N=2*p where p is prime) and lots (if N=p*q where p and q have 1404 and 145 digits respectively and you've no other information about them). The precise value of "lots" depends on the performance of your computer and how many of them you can use in concert. 

20180510, 11:03  #3  
Undefined
"The unspeakable one"
Jun 2006
My evil lair
2^{3}×3^{2}×5×17 Posts 
Quote:


20180510, 12:10  #4 
"Nuri, the dragon :P"
Jul 2016
Good old Germany
2×13×31 Posts 
We had this discussion (nearly the same topic) in the number theory discussion group.
You should read this thread. Anyway, I was able to fully factor an C311 after ~2700 secs by finding a P27 and P31. It was just luck, nothing more. Sometime you only get an P8 and the remaining cofactor is PRP. Or the number you enter is a semiprime; which would make it very very hard to factor it. Assuming the number is semiprime it might take some CPU weeks to fully factor the number, strongly depending on your computing power. 
20180510, 12:12  #5 
"Victor de Hollander"
Aug 2011
the Netherlands
498_{16} Posts 
Does your number have a special form, did you check for small factors (say <60 digits)?
If it doesn't have a special form and no small factors you will not factor it unless you work for the NSA. (Hit: the largest factorization using GNFS is RSA768 at 232 digits) 
20180510, 12:59  #6 
Romulan Interpreter
Jun 2011
Thailand
83×113 Posts 
We don't believe that. Please post logs. It took me few seconds to factor a well chosen 300 digits number...
Last fiddled with by LaurV on 20180510 at 13:00 
Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Predict the number of digits from within the factor for M1061  Raman  Cunningham Tables  12  20130617 21:21 
Predict number of digits in factor of (3^6071)/2  Raman  Cunningham Tables  43  20101114 09:03 
who can help me factor this 155 digits number  sinide  Factoring  12  20101109 01:05 
who can factor this 128 digits number?  aaa120  Factoring  19  20100904 09:16 
Predict number of digits in factor of 3,499+  lazy  Miscellaneous Math  0  20070622 12:14 