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
Some numbers that look the same when viewed upside down include 0, 1, and 8. Additionally, the number 6 becomes 9 when flipped upside down, and vice versa. The number 2 can appear similar to a 5 depending on the font, but it's not universally considered the same. Therefore, the primary numbers that maintain their appearance are 0, 1, and 8.
The answer is 888.Also:101111181808818
No. It's unusual because it reads the same way upside down, but it's not odd.
They both read the same when rotated 180 degrees.
11 and 88
If you're upside down then 25-up