Catalyzes the hydrolysis of the free cytosolic methylated adenosine nucleotide N(6)-methyl-AMP (N6-mAMP) to produce inositol monophosphate (IMP) and methylamine (PubMed:29884623, PubMed:30721978, PubMed:31318636). Is required for the catabolism of cytosolic N6-mAMP, which is derived from the degradation of mRNA containing N6-methylated adenine (m6A) (PubMed:29884623). Does not possess deaminase activity toward adenosine, AMP, N6-methyladenosine, or N6-mATP in vitro (PubMed:29884623). H(+) + H2O + N(6)-methyl-AMP = IMP + methylamine Binds 1 zinc ion per subunit. kcat is 0.21 sec(-1) with N(6)-methyl-AMP as substrate. Monomer. Slight reduction of root growth (PubMed:29884623). 10-fold increase of the ratio N(6)-methyl-AMP/AMP in leaf cells (PubMed:29884623). Belongs to the metallo-dependent hydrolases superfamily. Adenosine and AMP deaminases family.