Books like The Riemann Hypothesis
Karl Sabbagh
The Riemann Hypothesis is 304 pages, about 5 hours 34 minutes at 250 words a minute.
12 books to read next
How long each takes
The Music of the Primes 6.8 h 
Fermat's Last Theorem 6.2 h 
Prime Obsession 8.0 h 
Zero 4.7 h 
Principia Mathematica 7.5 h 
Mathematical Proofs 7.3 h 
Love and Math 6.1 h 
Number Theory 4.8 h 
Figuring 2.9 h 
Surreal Numbers 2.2 h 
E 4.2 h 
Proofs from the Book 3.8 h Bar height shows length. Estimated at 250 words a minute.