  The first part of this paper considers higher order CR invariants of three
dimensional hypersurfaces of finite type. Using a full normal form we give a
complete characterization of hypersurfaces with trivial local automorphism
group, and analogous results for finite groups. The second part considers
hypersurfaces of finite Catlin multitype and the Kohn-Nirenberg phenomenon in
higher dimensions. We give a necessary condition for local convexifiability of
a class of pseudoconvex hypersurfaces in $\mathbb C^{n+1}$.
