Polynomial identities and Azumaya loci for rational quantum spheres

We prove a number of structure and isomorphism results concerning the noncommutative Natsume-Olsen spheres 2 n 1 deformed along a skewsymmetric matrix 2 .These include (a) the fact that two C -algebras of the form 3 Mn are isomorphic precisely in the obvious cases; (b) the fact that m and n are recoverable from the isomorphism class of C. 2 m 1 /M n ; (c) the PI character, PI degree and Azumaya loci of C. 2 m 1 / for rational , along with a realization of their centers as (function algebras of)