Dephosphorylates the 5' and 2'(3')-phosphates of deoxyribonucleotides. Helps to regulate adenosine levels. a ribonucleoside 5'-phosphate + H2O = a ribonucleoside + phosphate Activated by ADP. Expressed at highest levels in testis. Also expressed in brain, skeletal muscle, kidney and heart. Belongs to the 5'-nucleotidase type 3 family.