GO:0052843:   inositol-1-diphosphate-2,3,4,5,6-pentakisphosphate diphosphatase activity
Catalysis of the reaction: inositol 1-diphosphate 2,3,4,5,6-pentakisphosphate + H2O = inositol 1,2,3,4,5,6-hexakisphosphate + phosphate + 2 H+.