I'm surprised nobody has answered you yet. I'll take a stab even though I'm far from an expert on file modes, umasks, and the like. I think that 16895 and 16877 are decimals which represent the permissions drwxrwxrwx and drwxr-xr-x. Here's the link from which I grabbed those values: http://www.madmongers.org/mailing-list/mailing-list/help-with-octal-math

So I guess the & 0222 is making sure that each dir is not writable?