8. In the six-digit decimal number $\overline{a_{1} a_{2} a_{3} a_{4} a_{5} a_{6}}$, each digit $a_{i}(1 \leqslant i \leqslant 6)$ is an odd number, and the digit 1 is not allowed to be adjacent (for example, 135131, 577797 satisfy the condition, while 311533 does not satisfy the condition), then the number of such six-digit numbers is $\qquad$.
When $a_{i}(1 \leqslant i \leqslant 6)$ does not contain the digit 1, the number of six-digit numbers $\overline{a_{1} a_{2} a_{3} a_{4} a_{5} a_{6}}$ is $4^{6}$; when $a_{i}(1 \leqslant i \leqslant 6)$ contains one 1, the number of six-digit numbers $\overline{a_{1} a_{2} a_{3} a_{4} a_{5} a_{6}}$ is $6 \cdot 4^{5}$; when $a_{i}(1 \leqslant i \leqslant 6)$ contains two 1s, the number of six-digit numbers $\overline{a_{1} a_{2} a_{3} a_{4} a_{5} a_{6}}$ is $C_{5}^{2} \cdot 4^{4}$; when $a_{i}(1 \leqslant i \leqslant 6)$ contains three 1s, the number of six-digit numbers $\overline{a_{1} a_{2} a_{3} a_{4} a_{5} a_{6}}$ is $C_{4}^{3} \cdot 4^{3}$, so the number of six-digit numbers $\overline{a_{1} a_{2} a_{3} a_{4} a_{5} a_{6}}$ that satisfy the condition is 13056.