Here's how to obtain the numerical value of the
chmod permissions of a directory on macOS. (Note that this method also works for files.)
stat -f %A directory/ # 755
Let's give it a try.
First, create a new directory and set its permissions.
mkdir directory/ chmod 777 directory/
Then we can retrieve its chmod number.
stat -f %A directory/ # 777
And here's how to retrieve it's chmod string value.
ls -n # drwxr-xr-x 2 501 20 64 Jun 21 13:57 directory/
This method also works for files.