Use "pdfinfo", it comes with poppler in my linux:
Code:
$ pdfinfo dantesinferno00dantuoft.pdf
Producer: Recoded by LuraDocument PDF v2.28
CreationDate: Thu Dec 6 09:34:21 2007
ModDate: Thu Dec 6 10:11:03 2007
Tagged: no
Pages: 372
Encrypted: no
Page size: 640 x 912 pts
File size: 37026003 bytes
Optimized: yes
PDF version: 1.5