With this proof about even perfect numbers, Euler finished the work begun by Euclid so long before. Their joint result – a collaboration spanning two millennia – should rightly be called the « Euclid-Euler Theorem ». This name, to be sure, has an alphabetical appeal to it, but it also hyphenates two of the greatest names from the history of mathematics. It is as thought Sophocles and Shakespeare had jointly written a play or Phidias and Michelangelo had jointly carved a statue.
Of course no book contrains such a play, and no museum holds such a statue. But the Euclid-Euler Theorem exists, a timeless monument to its two brilliant creators. In all of mathematics, there is nothing quite like it.
-William Dunham dans Euler : The master of us all à propos des travaux d’Euler sur les nombres parfaits