It travels 0.05 radians a second, and there are radians in an orbit. So the time for one orbit is seconds.
If it's speed is 550kmph and its distance to travel is 6000km, then it takes hours to cover that speed. Which is seconds!
So we now know how long it takes to complete and orbit, and we know an orbit is still 2pi radians!
So it's angular velocity is radians per second!