CZ-SK-MO 2021 Problem 4

Find all natural numbers $n$ for which equality holds $n + d (n) + d (d (n)) +... = 2021$ , where $d (0) = d (1) = 0$ and for $k> 1$ , $d (k)$ is the superdivisor of the number $k$ (i.e. its largest divisor of $d$ with property $d <k$ ).

(Tomáš Bárta)