Exhibits adenosine 5'-monophosphoramidase activity, hydrolyzing purine nucleotide phosphoramidates with a single phosphate group such as adenosine 5'monophosphoramidate (AMP-NH2) to yield AMP and NH2 (PubMed:16762638, PubMed:31990367). Hydrolyzes adenosine 5'-O-p-nitrophenylphosphoramidate (AMP-pNA) (PubMed:16762638). Hydrolyzes fluorogenic purine nucleoside tryptamine phosphoramidates in vitro (PubMed:31990367). May be involved in steroid biosynthesis (PubMed:18653718). May play a role in apoptosis (PubMed:16762638). adenosine 5'-phosphoramidate + H2O = AMP + NH4(+) Optimum pH is 7-8. High expression in liver and pancreas. Expression is significantly down-regulated in hepatocellular carcinoma (HCC) patients. Belongs to the HINT family.