thx, for good explenation. Description isn't so good for understanding.

Every coding people should or could know that modulo 2 sum of numbers or sum of these same numbers cubed both give the same result:-) So it's up to the coder to choose... unless he/she did it because he/she did not correctly read the description (unfotunately this often happens).

I think you're right there, parity won't change with pow (unless the power is 0)

Do you mean your solution used the sum of the digits instead of the sum of the cubes of the digits and it passed the tests in Swift? If that's true, open an issue saying that.

why is "chunk" used interchengably with "cube"?

Where? They're not. Cube is only used once, and it is used as the mathematical term.

Your instructions are wrong:

sum of the cubes of its digits is divisible by 2

That means, for instance, if you get a chunk of size 3 with the digits 123 as input, the sum of the cubes of its digits is 1 + 8 + 27 = 36 that's divisible by 2 and you should reverse it.