He held the presidency of the Moscow Mathematical Society between 1968 and 1970, and was elected a foreign member of the U.S. National Academy of Science, the American Academy of Arts and Sciences, the Royal Irish Academy, the American Mathematical Society and the London Mathematical Society.
Han var ordförande i Moskvas matematiska sällskap mellan 1968 och 1970 och har blivit utnämnd till utländsk ledamot i U.S. National Academy of Sciences, American Academy of Arts and Sciences, Royal Irish Academy, American Mathematical Society och London Mathematical Society.