Robert Daniel Carmichael

Robert Daniel Carmichael was an American mathematician known for his work in number theory, particularly in the study of prime numbers and special functions. He is best known for discovering Carmichael numbers—composite numbers that behave like prime numbers in certain mathematical tests for primality, challenging earlier assumptions. This work has implications in cryptography and number theory. Carmichael's research contributed to understanding the properties of numbers and improved methods for identifying primes, which are fundamental to secure digital communications today.