Here are two instances of an Kaprekar number
$ \text{9$ {}^{\wedge} $ 2 = 81 $ \&$ 8+1=9}$
$ \text{8$ {}^{\wedge} $ 3 = 512 $ \&$ 5+1+2=8}$
There are certainly more with a higher exponent , perhaps an infinite number of them.
However with the line of code below
FindInstance[ x^y == z && x > 1 && y > 1 && Total[IntegerDigits[z]] == x, {x, y, z}, Integers, 1] MMA V11.3 does not return a single instance. Is there anything wrong in this code or is it a limitation of the FindInstance function ?
