Aren't mersenne prime palindromes themselves? :razz:

[QUOTE=LaurV;585155]Aren't mersenne prime palindromes themselves? :razz:[/QUOTE]

I base 2 they are. In fact any n>1 is a palindrome in base n+1 and in base n-1 :grin:

[QUOTE=LaurV;585155]Aren't mersenne prime palindromes themselves? :razz:[/QUOTE]

All primes p not in [URL="https://oeis.org/A016038"]https://oeis.org/A016038[/URL] are palindromes in some base < p-1

Congrats to Serge and Ryan for the two smallest known Mega primes, prove with CHG at 28.7% factored of N+1

[URL="https://primes.utm.edu/primes/page.php?id=132705"]10^999999 - 1022306*10^287000 - 1[/URL]

[URL="https://primes.utm.edu/primes/page.php?id=132704"]10^999999 - 1087604*10^287000 - 1[/URL]

:banana: :banana:

[QUOTE=paulunderwood;587681]Congrats to Serge and Ryan for the two smallest known Mega primes, prove with CHG at 28.7% factored of N+1
[/QUOTE]
Two [I]largest [/I]known [I]less-than-Mega primes[/I], actually.
(The second one was found before search was called off, an incidental finding. :rolleyes: )

[CODE]...
10^999999+308267*10^292000+1 P 1000000 Batalov 02/2021
10^999999+593499 PRP 1000000 Peter Kaiser 02/2013
10^999999 C 1000000 --- a composite, smallest million-digit number
10^999999-172473 PRP 999999 Patrick De Geest 12/2016
10^999999-1022306*10^287000-1 P 999999 Propper,Batalov 09/2021
10^999999-1087604*10^287000-1 P 999999 Propper,Batalov 09/2021
...[/CODE]

[QUOTE=LaurV;585155]Aren't mersenne prime palindromes themselves? :razz:[/QUOTE]

Of course all repunits are “palindromes” per se, but in practical terms when a prime is a Mersenne, a Generalized Mersenne ( to other bases ), repunits, generalized repunits, they are not counted as palindromes in the database of “The primePages”

Congrats to Marc Wiseler and PrimeGrid for the "321" prime [URL="https://primes.utm.edu/primes/page.php?id=132678"]3*2^17748034-1[/URL] (5,342,692 decimal digits) ranked as the 18th largest known prime.

:banana: :banana: :banana:

[QUOTE=paulunderwood;587767]Congrats to Marc Wiseler and PrimeGrid for the "321" prime [URL="https://primes.utm.edu/primes/page.php?id=132678"]3*2^17748034-1[/URL] (5,342,692 decimal digits) ranked as the 18th largest known prime.

:banana: :banana: :banana:[/QUOTE]

Big congrats!!!!!

Another Riesel "other" number is [I]coming soon[/I].

It is a palindrome, chock full of "9"s (with a few others) and is neatly 1,234,567 decimal digits long

[QUOTE=Batalov;587870]Another Riesel "other" number is [I]coming soon[/I].

It is a palindrome, chock full of "9"s (with a few others) and is neatly 1,234,567 decimal digits long[/QUOTE]

I am looking forward to its revelation. The largest palindrome before this one had 490,001 digits. So 1,234,567 digits is quite amazing considering its crunching is done with generic modular reduction.

[QUOTE=paulunderwood;587879]I am looking forward to its revelation. The largest palindrome before this one had 490,001 digits. So 1,234,567 digits is quite amazing considering its crunching is done with generic modular reduction.[/QUOTE]

[URL="https://primes.utm.edu/primes/status.php"]https://primes.utm.edu/primes/status.php[/URL]

id 132704 and 132705 are palindromes.