I believe it has 502 pages. This is from a secondary source, not directly looking at the book, so I'm not 100% sure.
The Blood of Olympus by Rick Riordan has 502 pages in the hardcover edition.
There is no book called heroes if Olympus that is the book series name
There is no book called heroes if Olympus that is the book series name
There is no book called heroes if Olympus that is the book series name
Ocean of Blood has 232 pages.
Blood Canticle has 320 pages.
Lunch of Blood has 363 pages.
The Blood Spilt has 341 pages.
The Fallon Blood has 471 pages.
The Colour of Blood has 182 pages.
The Magic of Blood has 288 pages.
Troll Blood has 400 pages.