The debate will be televised by Russia 24 on Monday at 6 p.m.
Mikhalkov was registered as an official backer of Putin on Feb. 6, along with soccer player Andrei Arshavin, singer Nadezhda Babkina, musician Yury Bashmet and several hundred other famous sportsmen and artists. The film director has already called for Russian citizens to vote for Putin through his video blog.
After Putin announced last month that he may send proxies to represent him in presidential debates, Prokhorov said he would refuse to debate a proxy.
Each candidate in the presidential election is given nine hours of free airtime on four television stations and four radio stations. Printed forums for publishing election materials are also provided.
Prokhorov previously debated Communist Party candidate Gennady Zyuganov.
Candidates are allowed to appoint substitutes in debates, a rule previously utilized by Putin.