If you define 1 as a palindrome, then every number greater than one fits that qualification. There is no highest.
There can be no such number. The number 1 is a palindrome. So any number, n, can be expressed as a sum of n palindromes, each of which is equal to 1.
2
81
the largest integer of distinct power is 28
-3
The smallest 5 digit integer is -99999. The largest 5 digit integer is 99999. The sum is therefore 0.
This is not known for sure, but if Goldbach's conjectures are true, then 2.
Six. 1551 2442 3333 4224 5115 6006
1
30 distinct powers are 13,14, and 1523
15
2+(-2) =0
Because an integer is a whole number and the sum of any two or more whole numbers is always a whole number.