Four Hundred Forty One

In the standard surface code, a logical qubit at code distance $d$ uses

$n_q = (2d - 1)^2$

data plus measurement qubits, and corrects any error pattern of weight up to $(d-1)/2$. Below the per-step threshold of about 0.57%, the logical error rate falls off sharply as $d$ grows.

A team builds one logical qubit at $d = 11$. How many physical qubits, and how many simultaneous errors can it correct?