18181...18181 (77-digits)

This number is a prime.

                                                                     1818181
8181818181 8181818181 8181818181 8181818181 8181818181 8181818181 8181818181

+ A smoothly undulating tedradic palindromic prime which is (7*11) digits in length and has a sum of digits equal to 7^3. Note that the difference between the two digits it uses equals 7. [Necula]

Printed from the PrimePages <t5k.org> © G. L. Honaker and Chris K. Caldwell