  The neutron and proton odd-even mass differences are systematically studied
with Hartree-Fock+BCS (HFBCS) calculations with Skyrme interactions and an
isospin dependent contact pairing interaction. The strength of pairing
interactions is determined to reproduce empirical odd-even mass differences in
a wide region of mass table. By using the optimal parameter, we perform global
HF+BCS calculations of nuclei and compare with experimental data. The
importance of isospin dependence of the pairing interaction is singled out for
odd-even mass differences in medium and heavy isotopes. The proton and neutron
radii are studied systematically by using the same model.
