Hydrolase that converts various nucleotide triphosphates (NTPs) to the corresponding nucleotide monophosphates and diphosphate, and nucleotide diphosphates to nucleotide monophosphates and inorganic phosphate. Has a marked preference for cytosine ribonucleoside 5'-diphosphate (CDP) and cytosine ribonucleoside 5'-triphosphate (CTP). Has lower activity towards the deoxyribose nucleotides dCDP and dCTP, and towards dGDP, TDP and UDP. Inhibited by zinc, calcium or copper ions. Optimum pH is 9.0-9.5. Monomer. Belongs to the Nudix hydrolase family.