An old Soviet Movie (1972) based on the story "The Devil and Simon Flagg" by Arthur Porges. You can read the story here: http://simonsingh.net/books/fermats-last-theorem/wacky-fermat-stuff/devilish-short-story/
Scriptwriter: S. Raitburt
Director: V. Shuplyakova
Cast:
The mathematician: V. Shestakov
The Devil: A. Kaidanovsky
Mathematician's wife: A. Pokrovskaya