The theory of hole superconductivity proposes that superconductivity originates in the fundamental electron-hole asymmetry of condensed matter and that it is an 'undressing' transition. Here we propose that a natural consequence of this theory is that superconductors behave as giant atoms. The model predicts that the charge distribution in superconductors is inhomogeneous, with higher concentration of negative charge near the surface. Some of this negative charge will spill out, giving rise to a negative electron layer right outside the surface of the superconductor, which should be experimentally detectable. Also superconductors should have a tendency to easily lose negative charge and become positively charged. Macroscopic spin currents are predicted to exist in superconducting bodies, giving rise to electric fields near the surface of multiply connected superconductors that should be experimentally detectable.