  We show that the Szekeres system with cosmological constant admits a
sufficient number of conservation laws, which allow to claim the integrability
of the system. The main novelty in this investigation is that we find that the
unique attractor of the Szekeres system is the isotropic inhomogeneous de
Sitter (-like) universe, contrary to the original system in which the
attractors describe Kantowski-Sachs (-like) spacetimes. We also study the
existence of quantum corrections and the emergence of classicality by
considering the linear and quadratic conserved quantities at the quantum level.
We perform an analysis considering different approaches, involving the Bohmian
quantum potential and a probability analysis. The result is that there are no
quantum corrections for the quadratic integrals, while there exists a linear
case for which we find quantum corrections.
