Find the derivative of the function and evaluate the derivative at the given value of a$.$

$h(x)=x^{\sqrt[\phantom{2}]{x}}$;$a=4$

Find the derivative of the function.

$\frac{d}{dx}{x}^{\sqrt[\phantom{2}]{x}}=$

Evaluate the derivative at the given value of a$.$

$h^{\text{'}}(a)=$