\[- 1\frac{3}{5}m^{4}n^{3} \cdot \left( - \frac{1}{2}m^{3}p^{6} \right)^{3} =\]
\[= - \frac{8}{5}m^{4}n^{3} \cdot \left( - \frac{1}{8} \right)m^{9}p^{18} =\]
\[= \frac{1}{5}m^{13}n^{3}p^{18}\]