motor power and torque

I would like to know these for reference sake.

I recall a 20 to 25 kgcm torque for a similar geared motor this is 2 Nm,  (20kg cm/100cm per m x 9.81 Newtons per Kg)

Now power conversion formula is power (kw) = torque(Nm) x rotation speed (rpm) / 9.54

so this motor at 6 rpm is  2 x 6 /9.5 = about 1 kw????
But this is a 20 watt motor. Maybe that formula was for high speed engines for things such as cars?