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Old 2021-09-23, 00:13   #12
slandrum
 
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Quote:
Originally Posted by bur View Post
Thanks for the explanations about the necessity of an odd number of digits.
Well - to be precise it's not that it needs to be an odd number of digits, it's that it needs to be a prime number of digits.
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Old 2021-09-23, 00:29   #13
Batalov
 
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Quote:
Originally Posted by slandrum View Post
Well - to be precise it's not that it needs to be an odd number of digits, it's that it needs to be a prime number of digits.
That is funny (if it was supposed to be a joke) - but incorrect.
9-digit palindrome primes exist and there are tons of them. For example, 100030001.
1234567 is also, obviously, not prime
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Old 2021-09-23, 01:32   #14
slandrum
 
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Originally Posted by Batalov View Post
That is funny (if it was supposed to be a joke) - but incorrect.
9-digit palindrome primes exist and there are tons of them. For example, 100030001.
1234567 is also, obviously, not prime
Sorry - I was completely spaced and thinking of repunit primes.
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