A palindromic number is a 'symmetrical' number like 16461, that remains the same when its digits are reversed. The term palindromic is derived from palindrome, which refers to a word like rotor that remains unchanged under reversal of its letters. http://en.wikipedia.org/wiki/Palindromic_number
An ambigram.
Ambigram
1961
SOS
SOS !
9116
The answer is 888.Also:101111181808818
They both read the same when rotated 180 degrees.
No. It's unusual because it reads the same way upside down, but it's not odd.
If you're upside down then 25-up
11 and 88
a palindrome