20201117, 23:14  #45  
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
9,209 Posts 
Quote:
Quote:
Your code took 3 seconds to check 1105 to see if it is prime. I asked Wolfram Alpha for a random prime in the highest range that Excel can natively handle. It gave me: 162254563 My little "PrimeToolKit" excel can check for prime, factor, or yield primes in a given range. It took 3 seconds to generate 1144 primes from 162254563 to 162277063 (that includes display overheads, such as clearing ~10000 cells). I asked WA for 2 primes from 9000 to 10000. I calculated the product and then fed that into my code. The factoring happened so quickly as to appear instantaneous and was less than the time resolution of excel. My code is not the best by far. But it works nice for small numbers. 

20201117, 23:48  #46 
"Mike"
Aug 2002
5×7×227 Posts 
Did you forget to attach it?

20201118, 00:07  #47 
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
9,209 Posts 

20201118, 02:46  #48  
Feb 2017
Nowhere
1053_{16} Posts 
Quote:
This is one case where man really can beat machine. The final decimal digit is 5 in a number greater than 5. Not prime. Done. two, three. 

20201118, 23:15  #49  
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
9,209 Posts 
Quote:
The Excel file with the VBA is in the zip. 

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