Catalyzes the hydrolysis of the N-glycosidic bond of diverse pyrimidine and purine nucleotide 5'-monophosphates, to form ribose 5-phosphate and the corresponding free base. Can use AMP, GMP, IMP, CMP, dTMP and UMP as substrates. Cannot catalyze the reverse reactions. May contribute to nucleoside pool homeostasis by degrading excess nucleotides and feeding back the ribose moiety to catabolism. a pyrimidine ribonucleoside 5'-phosphate + H2O = a pyrimidine nucleobase + D-ribose 5-phosphate AMP + H2O = adenine + D-ribose 5-phosphate GMP + H2O = D-ribose 5-phosphate + guanine CMP + H2O = cytosine + D-ribose 5-phosphate H2O + IMP = D-ribose 5-phosphate + hypoxanthine H2O + UMP = D-ribose 5-phosphate + uracil dTMP + H2O = 2-deoxy-D-ribose 5-phosphate + thymine Belongs to the LOG family.