[ColinWright]

Except that by count of pages, Euler is the most published mathematician ever.

Who is the most prolific mathematician? Either Leonhard Euler, if counting by single authorship, or Paul Erdös, if counting by collaborative publications. -- http://wiki.answers.com/Q/Who_is_the_most_prolific_mathemati...

The most prolific mathematician of all time, publishing close to 900 books. -- http://www.guardian.co.uk/culture/2010/apr/11/the-10-best-ma...

Euler's work in mathematics is so vast that an article of this nature cannot but give a very superficial account of it. He was the most prolific writer of mathematics of all time. -- http://www-gap.dcs.st-and.ac.uk/~history/Biographies/Euler.h...

He is considered to be the pre-eminent mathematician of the 18th century, and one of the greatest mathematicians ever to have lived. He is also one of the most prolific mathematicians ever; his collected works fill 60–80 quarto volumes. -- https://en.wikipedia.org/wiki/Leonhard_Euler