For the reaction \( \mathrm{A} \to \mathrm{B} \), the rate constant \( k \) (in \( \text{s}^{-1} \)) is given by \( \log_{10} k = 20.35 - \frac{(2.47 \times 10^{3})}{T} \).
The energy of activation in \( \text{kJ mol}^{-1} \) is ________. (Nearest integer) [Given: \( R = 8.314 \, \text{J K}^{-1}\text{ mol}^{-1} \)]