\[\boxed{\mathbf{787}\mathbf{.}}\]
\[1)\ f(x) = x^{6}\]
\[f^{'}(x) = \left( x^{6} \right)^{'} = 6x^{6 - 1} = 6x^{5}\]
\[2)\ f(x) = x^{7}\]
\[f^{'}(x) = \left( x^{7} \right)^{'} = 7x^{7 - 1} = 7x^{6}\]
\[3)\ f(x) = x^{11}\]
\[f^{'}(x) = \left( x^{11} \right)^{'} = 11x^{11 - 1} = 11x^{10}\]
\[4)\ f(x) = x^{13}\]
\[f^{'}(x) = \left( x^{13} \right)^{'} = 13x^{13 - 1} = 13x^{12}.\]