An element M crystallises in a body centred cubic unit cell with a cell edge of $300 \,\mathrm{pm}$. The density of the element is $6.0 \mathrm{~g} \mathrm{~cm}^{-3}$. The number of atoms present in $180 \mathrm{~g}$ of the element is ____________ $\times 10^{23}$. (Nearest integer)