3 Cu0 + 4 HNVO3 3 CuI(NVO3) + NIIO + 2 H2O

This is an oxidation-reduction (redox) reaction:

3 Cu0 - 3 e- 3 CuI (oxidation)

NV + 3 e- NII (reduction)

Cu is a reducing agent, HNO3 is an oxidizing agent.