Find the largest possible positive integer \(x_{10}\) less than \(2021_{10}\) such that \(d(x_{11})^2=4d(x_{13})\).
Notation clarification: \(x_{k}\) is \(x\) in base \(k\)
\(d(x_{k})\) is the sum of the digits of \(x\) in base \(k\)
Note: This can easily be done with simple coding.
+10 
