Bibliophilia Alert: These are the longest books of all times 

Number of pages:  10,710

Number of pages:  17,868

In the Realms of the Unreal by John MacGregor Number of pages:  15,145

Number of pages:  7,443

Number of pages:  4,215

Zettel’s Traum by Arno Schmidt Number of pages:  1,334

Number of pages:  840,000