In the film the character of Ramanujan is played by the young and talented Dev Patel and that of his wife Janaki by the graceful Devika Bhise. The famous actor Jeremy Irons plays the role of Professor G H Hardy. Others in the cast include Kevin Mcnally, Arundhati Nag, Dhritiman Chaterji, Shazad Latif, Anthony Calf, Roger Narayan, Jeremy Northam, Stephen Fry, Toby Jones and others.