\(m_m=207 m_e\)
When all other quantities remain uncharged,
\(r \propto \frac{n^2}{m}\) and \(E \propto \frac{m}{n^2}\)
\(\therefore r_m=\frac{r_e m_e}{m_m}=\frac{0.53 \times 10^3}{207}=2.56 \times 10^{-13} m\)
\(\text { and } E_m=\frac{E_e m_m}{m_e}=-(13.6 \times 207)=-2.8\; keV\)