For introduction, Ethiointegers are integers which get reversed when multiplied by another number.
2178 * 4 = 8712
1089 * 9 = 9801
I couldn't find such numbers, even by another name anywhere else except in one journal which I think is not electronically accessible.
My question: Has numbers like this been treated anywhere? If so, what interesting properties do they have?
[E.g. One property I consider interesting: sumofdivisors(1089) = 1729 = 1728 + 1 (Hardy's taxi number 12^3 + 1^3, more about this sum ), also 1728 is a rearrangement of 2178!]
[Added later] Eulertotient(2178) = Eulertotient(1089)