The son of two mathematics teachers from the Hungarian capital of Budapest, Erdös devoted his life to mathematics to an unequalled degree. He was educated at the University of Budapest where he obtained his PhD in 1934. Sensing difficult political times ahead, Erdös moved to Manchester on a four-year fellowship. Shortly before the outbreak of war he left for America. At the height of the McCarthy era he was denied a reentry permit after attending a conference in Amsterdam. Erdös then settled in Israel for several years until, in the 1960s, he was allowed an American visa once more.

Erdös was something of an eccentric. With no official job and no family, he lived out of a suitcase and traveled from one mathematical center to another. His life was spent working up to 20 hours a day on mathematical problems, usually with colleagues. In the process he produced over 1500 papers. He lived on lecture fees, prizes, grants, and the hospitality of his wide circle of collaborators. He wrote up to 1500 letters a year and had more than 250 published collaborators.