\[\frac{6^{15}}{2^{13} \cdot 3^{13}} = \frac{(2 \cdot 3)^{15}}{2^{13} \cdot 3^{13}} = \frac{2^{15} \cdot 3^{15}}{2^{13} \cdot 3^{13}} =\]
\[= 2^{15 - 13} \cdot 3^{15 - 13} = 2^{2} \cdot 3^{2} =\]
\[= 4 \cdot 9 = 36.\]