It is shown that a general model of athermal random copolymers in an equilibrium state is related to an appropriately generalized n --> 0 spin vector model, with each spin having 2n components. By adjusting various coupling constants in the model, one can control various densities such as bond densities of each type and copolymer density, average copolymer size, average block size, etc. The model is solved in a mean-field approximation to study the complete phase diagram and to calculate the free energy and the entropy and the entropy of mixing of copolymers in an athermal solution.