In recent years, the N = 90 isotones have been investigated to a large extent in relation to studies of quantum phase transitions. In this paper, we use the mean field approach with pairing-deformation self-consistent total Routhian surface (TRS) calculations to study the N = 90 isotones and neighboring nuclei. The important probes, such as moments of inertia, quadrupole moments, the energy ratio of E(4(1)(+))/E(2(1)(+)), and octupole and hexadecapole degrees of freedom are considered and the calculated results are compared with the available experimental data. From a microscopic point of view, the N = 90 isotones characterize the onset of the deformed region and are very well described by mean field calculations. The results are compared with those from other studies in beyond mean field approximations. Shape coexistence phenomena in the region of interest are discussed.