The molar conductivities at infinite dilution of barium chloride, sulphuric arid and hydrochloric acid are 280,860 and $426 \mathrm{Scm}^2 \mathrm{~mol}^{-1}$ respectively. The molar conductivity at infinite dilution of barium sulphate is $\_\_\_\_$ $\mathrm{S} \mathrm{cm} \mathrm{mol}^{-1}$ (Round off to the Nearest Integer).