13) (3^4)^4. (3^8)^7/(3^5)^9 =

$$ \frac{(3^4)^4 \cdot (3^8)^7}{(3^5)^9} = \frac{3^{4 \cdot 4} \cdot 3^{8 \cdot 7}}{3^{5 \cdot 9}} = \frac{3^{16} \cdot 3^{56}}{3^{45}} = \frac{3^{16+56}}{3^{45}} = \frac{3^{72}}{3^{45}} = 3^{72-45} = 3^{27} = 7625597484987 $$

Ответ: 7625597484987