20181205, 10:18  #1 
Mar 2018
2×5×53 Posts 
A yuge number
(2^78914561)*10^2375565+2^78914551
Is this number a probable prime or which is the smallest factor? 
20181205, 11:22  #2 
Jun 2003
3×17×101 Posts 

20181205, 13:23  #3 
Jun 2003
141F_{16} Posts 
No factors till 32*10^9. Quitting my attempt.

20181205, 13:36  #4  
"Forget I exist"
Jul 2009
Dumbassville
2^{6}×131 Posts 
Quote:


20181206, 11:16  #5 
Mar 2018
2×5×53 Posts 
Program

20181206, 13:29  #6 
Jun 2003
3·17·101 Posts 

20181206, 13:59  #7 
Mar 2018
2×5×53 Posts 
code

20181206, 14:42  #8 
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
5^{2}×401 Posts 
Go write it for yourself. Prove to us that you are willing to do some actual work in proving your number schemes. We have been spoonfeeding your.
Last fiddled with by Uncwilly on 20181206 at 14:43 
20181206, 15:45  #9 
Jun 2003
12037_{8} Posts 
Code:
mod_check(p)=my(r=Mod(2,p)^7891455); (r*21)*Mod(10,p)^2375565+r==1 forprime(p=2,,if(mod_check(p),print(p))) 
20181206, 15:50  #10 
Mar 2018
2·5·53 Posts 
code

20181206, 15:56  #11 
"Serge"
Mar 2008
Phi(4,2^7658614+1)/2
2·4,787 Posts 
Why not use Sage for that, though?

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