'zipsplit' command in Linux

[aleahim]

Hi,

I have a *.pdf file with a 3.2MB size.
I used the zip command in Linux to make it a zip file.

zip -rm name_archive pdf_file

Then, when I want to use the zipsplit command I receive the massage: "Entry too big to split(pdf_file)".

zipsplit -n 1440000 zip_file

Do you know what happening? Because with other file (non *.pdf) the zipsplit command works.

Many thanks,
mihaela