$\left\lfloor(\sqrt[3]{28}-3)^{-n}\right\rfloor$ is not divisible by 6

Question

let $n$ be a positive integer.
Prove that the following expression:

$$\left\lfloor(\sqrt[3]{28}-3)^{-n}\right\rfloor$$

is not divisible by 6.

$\lfloor x\rfloor$ is the greatest integer less than or equal to $x$.