We consider a class of Schr\"odinger operators on $\mathbb R^N$ with
radial potentials. Viewing them as self-adjoint operators on the
space of radially symmetric functions in $L^2(\mathbb R^N)$, we show
that the following properties are generic with respect to the
potential:
(P1) the eigenvalues below the essential spectrum are nonresonant
(that is, rationally independent) and so are the square roots
of the moduli of these eigenvalues;
(P2) the eigenfunctions corresponding to the eigenvalues below the
essential spectrum are algebraically independent on any nonempty
open set.
The genericity means that in suitable topologies the potentials
having the above properties form a residual set. As we
explain, (P1), (P2) are prerequisites for some applications of
KAM-type results to nonlinear elliptic equations. Similar properties
also play a role in optimal control and other problems in
linear and nonlinear partial differential equations.