Unzip file issue: FileName.rar.001

I have 22 .rar files with name ending like this:

FileName.rar.001

FileName.rar.002

...

FileName.rar.010

..

FileName.rar.021

FileName.rar.022

when I unzip then, it shows error message: "...FileName.rar.001: Unexpected end of archive"

any one has good suggestions?

thank you!