Shakuntala Devi, an Indian mathematical wizard known as “the human computer” for her ability to make incredibly swift calculations, died on Sunday in Bangalore, India. She was 83.

The cause was respiratory and cardiac problems, said D. C. Shivadev, a trustee of the Shakuntala Devi Educational Foundation Public Trust.

Ms. Devi demonstrated her mathematical gifts around the world, at colleges, in theaters and on radio and television. In 1977, at Southern Methodist University in Dallas, she extracted the 23rd root of a 201-digit number in 50 seconds, beating a Univac computer, which took 62 seconds.