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
Blood or Mead has 214 pages.
The Blood Book has 248 pages.
Blood Hunt has 384 pages.
Blood of Amber has 215 pages.
Blood Beast has 262 pages.
Thieves of Blood has 352 pages.
Blood Noir has 340 pages.
Blood Sisters has 608 pages.