Converts adenosine 3'-phosphate 5'-phosphosulfate (PAPS) to adenosine 5'-phosphosulfate (APS) and 3'(2')-phosphoadenosine 5'- phosphate (PAP) to AMP. Regulates the flux of sulfur in the sulfur-activation pathway by converting PAPS to APS. Confers resistance to lithium. adenosine 3',5'-bisphosphate + H2O = AMP + phosphate Belongs to the inositol monophosphatase superfamily.