It is desired to scale-up a fermentation from $1L$ to $1000L$ vessel by maintaining a constant power-to-volume ratio. The small fermenter is operated at an agitator speed of $300$ rotations per minute $(\textit{rpm})$. If the value of scale up factor is $10$, agitator speed in $\textit{rpm}$ (rounded off to the nearest integer) for the large fermenter is _________.