\[\frac{36^{5}}{2^{9} \cdot 3^{8}} = \frac{\left( 6^{2} \right)^{5}}{6^{8} \cdot 2} = \frac{6^{10}}{6^{8} \cdot 2} =\]
\[= \frac{6^{2}}{2} = \frac{36}{2} = 18\]