We must convert the rotational speed in $\mathrm{rpm}$ to speed in terms of radians per second to be consistent. Recall that the angular measure of radians is a dimensionless quantity.

$$\begin{gathered} \mathrm{P}=\mathrm{T\omega } \\ =(886.0797 \mathrm{N}-\mathrm{m})\times (600 \mathrm{rev}/\min )(2\mathrm{\pi } \mathrm{rad}/\mathrm{rev})(1 \min /60 \mathrm{s}) \\ =(886.0797 \mathrm{N}-\mathrm{m})\times (62.831853 \mathrm{rad}/\mathrm{s}) \\ =55,674.02953 \mathrm{N}-\mathrm{m}/\mathrm{s} \\ =55,674 \mathrm{W}=\mathbf{55}\mathbf{.}\mathbf{7}\mathbf{ }\mathbf{kW} \end{gathered}$$