\[\left( - mn^{2} \right)^{4} \cdot \left( - 2m^{5}n \right)^{2} \cdot \left( m^{5} \right)^{3} \cdot \left( 6n^{4} \right)^{2} =\]
\[= m^{4}n^{8} \cdot 4m^{10}n^{2} \cdot m^{15} \cdot 36n^{8} =\]
\[= 144m^{29}n^{18}.\]