6) 25⁴ ⋅ 125¹⁰ 5³⁷.

6) $$\frac{25^4 \cdot 125^{10}}{5^{37}} = \frac{(5^2)^4 \cdot (5^3)^{10}}{5^{37}} = \frac{5^8 \cdot 5^{30}}{5^{37}} = \frac{5^{8+30}}{5^{37}} = \frac{5^{38}}{5^{37}} = 5^{38-37} = 5^1 = 5$$

Ответ: 5