Cleaves a beta-phosphate from the diphosphate groups in PP-InsP5 (diphosphoinositol pentakisphosphate) and [PP]2-InsP4 (bisdiphosphoinositol tetrakisphosphate). Also catalyzes the hydrolysis of dinucleoside oligophosphates, with Ap6A and Ap5A being the preferred substrates. The major reaction products are ADP and p4a from Ap6A and ADP and ATP from Ap5A. diphospho-myo-inositol polyphosphate + H2O = myo-inositol polyphosphate + phosphate. H2O + P(1),P(6)-bis(5'-adenosyl) hexaphosphate = adenosine 5'-tetraphosphate + ADP + 2 H(+) H2O + P(1),P(5)-bis(5'-adenosyl) pentaphosphate = ADP + ATP + 2 H(+) kcat is 2 sec(-1) for Ap6A. kcat is 1.7 sec(-1) for Ap5A. Optimum pH is 7.6. Monomer. Belongs to the Nudix hydrolase family. DIPP subfamily.