For combustion of one mole of magnesium in an open container at 300 K and 1 bar pressure, $\Delta$_CH^$\Theta$ = $-$601.70 kJ mol^$-$1, the magnitude of change in internal energy for the reaction is __________ kJ. (Nearest integer)

(Given : R = 8.3 J K^$-$1 mol^$-$1)