It is quite easy to figure out using dimensional analysis. The SI unit of the dynamic viscosity commonly denoted $\eta$ or $\mu$ is the pascal-second (also called poiseuille named after Jean-Léonard-Marie Poiseuille). Therefore its dimension is
$$\left[\eta\right] = \mathsf{M}\mathsf{L}^{-1}\mathsf{T}^{-1}.$$
Since the kinematic viscosity $\nu$ is a diffusivity coefficient
$$\left[\nu\right] = \mathsf{L}^2\mathsf{T}^{-1}.$$
Back to your equation:
$$
\eta \propto \frac{(\rho_\mathrm{s}-\rho_\mathrm{l})gr^2}{v} \Longrightarrow
\left[\eta\right] = \frac{[\rho][g][r]^2}{[v]} = \frac{(\mathsf{M}\mathsf{L}^{-3})(\mathsf{L}\mathsf{T}^{-2})(\mathsf{L})^2} {\mathsf{L}\mathsf{T}^{-1}} = \mathsf{M}\mathsf{L}^{-1}\mathsf{T}^{-1}
$$
Thus your equation provides a relation for the dynamic viscosity.