What is the record for the maximum number of main rotor blades in a helicopter?

I can't answer what the record number of main rotor blades is but these three helicopters are the some of the largest helo's in the world and the last has 10 main rotor blades although it has no tail rotor so it depends on your definition of main rotor I guess.

Sikorsky S-64 Sky crane - Has 7 main rotor blades

Mil Mi-26 - Has 8 main rotor blades

Mil Mi-12 - Has 10 main rotor blades - was only really a prototype.