15 (26)3:2 (23)2.22 =

15. $$\frac{(2^6)^3 : 2}{(2^3)^2 \cdot 2^2} = \frac{2^{6\cdot3} : 2}{2^{3\cdot2} \cdot 2^2} = \frac{2^{18} : 2}{2^6 \cdot 2^2} = \frac{2^{18-1}}{2^{6+2}} = \frac{2^{17}}{2^8} = 2^{17-8} = 2^9 = 512$$

Ответ: 512