I need some help solving the next permutations group equation: $$ x^{20} = \sigma $$ where
$$ \sigma = \begin{pmatrix} 1 & 2 & 3 & 4 & 5 & 6 & 7 & 8 & 9 & 10 & 11 & 12 & 13 \\ 7 & 4 & 5 & 6 & 1 & 8 & 3 & 10 & 12 & 2 & 13 & 9 & 11 \end{pmatrix}. $$
I've already found out that the product of disjoint cycles is $(1 \ 7 \ 3 \ 5)(2 \ 4 \ 6 \ 8 \ 10)(9 \ 12)(11 \ 13)$, the order is $order(\sigma)=20$ and the sign is $sgn(\sigma)=1$, but I don't know how to use all these to solve the equation above.
Well, cycles of odd length are even permutations, and cycles of even length are odd permutations. Here we have three cycles of even length and one cycle of odd length, and so $\operatorname{sign}(\sigma)=(-1)^3\cdot1=-1$. On the other hand, $\operatorname{sign}(x^{20})=(\operatorname{sign}(x))^{20}=1$, and so the equation has no solutions at all.