How many pages should Victor Hugo's "The Hunchback of Notre Dame" be?

That does seem short! I have two different copies of this book. One is 590 pages (Notre-Dame de Paris, Oxford World's Classics). The other is a mass market paper back which is 496 pages (Penguin Classics). I really like the translation of the Oxford and it has thorough footnotes and supplemental materials. Both can be purchased on Amazon.