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). {ECO:0000269|PubMed:16762638, ECO:0000269|PubMed:18653718, ECO:0000269|PubMed:31990367}. This is the function of HINT2 (histidine triad nucleotide binding protein 2, ENSG00000137133).