The book is now available! 19
(another Prime Pages' Curiosity)
Prime Curios!
Curios: Curios Search:
 

Participate:
Share
Single Curio View:   (Seek other curios for this number)

 

19 is the only known number for which both (10^n-1)/9 and (10^n+1)/11 are primes.

 

  Submitted: 2004-09-05 23:50:17;   Last Modified: 2008-01-30 11:28:00.



Prime Curios! © 2000-2017 (all rights reserved)