  Introducing n right-handed neutrinos to the Standard Model yields, in
general, massive active neutrinos. We give explicit parametrizations for the
involved mixing and coupling matrices in terms of physical parameters for both
the top-down and the bottom-up approach for arbitrary n. Bounds on the complex
mixing angles in the bottom-up approach from perturbativity of the Yukawa
couplings to charged lepton flavor violation are discussed. As a novel
illustration of possible effects from n != 3, we extend the neutrino anarchy
framework to arbitrary n; we show that while the anarchic mixing angles are
insensitive to the number of singlets, the observed ratios of neutrino masses
prefer small n for the simplest linear measure.
