The volume charge density of a sphere of radius $6 \mathrm{~m}$ is $2 \,\mu \mathrm{C} \,\mathrm{cm}^{-3}$. The number of lines of force per unit surface area coming out from the surface of the sphere is _______________ $\times 10^{10} \,\mathrm{NC}^{-1}$.

[Given : Permittivity of vacuum $\epsilon_{0}=8.85 \times 10^{-12} \,\mathrm{C}^{2}\, \mathrm{~N}^{-1}-\mathrm{m}^{-2}$ )