11
11
There are the same number: any twelve digit palindrome is just an eleven digit palindrome with its central digit repeated. In general, if we are considering numbers of n digits: For even values of n, the number of palindromes is 9 x 10n/2 - 1 For odd values of n, the number of palindromes is 9 x 10(n-1)/2
2 digit number
Highest 2-digit number = 99 Highest 1-digit number = 9 Highest possible sum from 2, 2-digit numbers = 198 Highest possible sum from 2, 1-digit numbers = 18
The only number that fits those conditions is... 55
1 to 1000. Pilandromic 108
It is 77.It is 77.It is 77.It is 77.
11
11
The only 2-didgit palindromic prime is 11.
There are the same number: any twelve digit palindrome is just an eleven digit palindrome with its central digit repeated. In general, if we are considering numbers of n digits: For even values of n, the number of palindromes is 9 x 10n/2 - 1 For odd values of n, the number of palindromes is 9 x 10(n-1)/2
A palindromic number is the same forwards as backwards. In the case of a two-digit number, that means the two digits are the same: 11, 22, 33, 44, 55, 66, 77, 88, and 99. The only one that is prime is 11, since the others are all multiples of 11.
2 digit number
Highest 2-digit number = 99 Highest 1-digit number = 9 Highest possible sum from 2, 2-digit numbers = 198 Highest possible sum from 2, 1-digit numbers = 18
Since the greatest digit is 9 and the greatest 2-digit number is 99, the product of them is 891.
It is 891.