In Rodriguez-Gomez et al. (2022), we present a first exploration of the angular momentum content of galaxies in the IllustrisTNG cosmological simulation. In this paper, we not only show that the stellar specific angular momenta of IllustrisTNG galaxies are consistent with observational constraints, but also report some intriguing correlations between the angular momentum of a galaxy, the spin of its host dark matter halo, and the mass of the black hole at the galactic center. In particular, we show that galaxies that formed within faster spinning halos, as well as those hosting less massive black holes at their centers, tend to have a higher angular momentum content.