Today would be the 100th birthday of legendary Hungarian mathematician Paul Erdős. Among his many accomplishments, Erdős is perhaps best known for being the most published mathematician of all time (1500+ papers), and his extensive collaborations with other mathematicians, which is reflected in the establishment of the Erdős number.
[He] was an influential mathematician, who spent a large portion of his later life living out of a suitcase and writing papers with those of his colleagues willing to give him room and board. He published more papers during his life (at least 1,525) than any other mathematician in history.
The idea of the Erdős number was created by the mathematician’s friends as a humorous tribute to his enormous output as one of the most prolific modern writers of mathematical papers. The Erdős number has become well known in scientific circles as a tongue-in-cheek measurement of mathematical prominence.