Final answer:
The number assigned to the dialyzer indicating the membrane's permeability is the filtration coefficient.
Step-by-step explanation:
The number assigned to a dialyzer indicating the membrane's permeability for a particular molecule or particle is called the
filtration coefficient.
The filtration coefficient is a measure of how easily a substance can pass through the dialyzer membrane. It is calculated by dividing the rate of solute transfer across the membrane by the pressure difference driving the transfer.