The thermodynamic and structural properties of a sticky hard sphere-hard sphere heteronuclear dimer fluid was studied using the multidensity Ornstein-Zernike integral equation theory. In this formalism, a monodisperse system of the heteronuclear dimer was modeled as an equal molar binary mixture of associating sticky hard sphere and hard sphere particles in the complete association limit. A general analytical solution to the model was obtained within the Percus-Yevick and polymer Percus-Yevick approximations for any degree of association including the complete association limit. Explicit analytical expressions for the contact values of correlation functions were obtained. Further, correlation functions beyond the hard core region were also calculated. The Helmholtz energy and pressure of the heteronuclear dimer are obtained via the energy route. The critical temperature, critical density, and phase coexistence of the fluid are also obtained.