The Oxen of the Sun (or how Archimedes’ number came up 2000 years too late)

Abstract

Thus begins an epigram written in the third century B.C. by the famous Greek mathematician Archimedes, and communicated to Eratosthenes and his colleagues in Alexandria. The epigram goes on to describe an arithmetical problem involving the determination of the number of cattle in a certain herd, starting from nine stated constraints. The epigram also states that one who can solve the problem would be "not unknowing nor unskilled in numbers, but still not yet to be numbered among the wise." Nothing could be more apt, as it turns out. The problem was not solved until 1965, when a computer was brought to bear on the problem. The solution is a number having 206,545 digits! Clearly, Archimedes cannot himself have known the solution, but the wording of the epigram makes it clear that he knew it had to be pretty big. Doubtless he had quite a chuckle at the thought of the poor Alexandrians trying to find the solution.

“Compute, O friend, the number of the oxen of the Sun, giving thy mind thereto, if thou hast a share of wisdom.”