Nix: Split a file by line number

I’ve been using the split command for a while to split a file into multiple files with at most say 1000 lines per file:

>>> wc --lines file.txt
2325 file.txt
>>> split --lines 500 file.txt file
>>> wc --lines file??
1000 fileaa
1000 fileab
325 fileac
2325 total

What I didn’t realize is that there are now options to use a numeric suffix rather than alphabetic, and also to specify the file extension to use:

>>> split --lines 500 --numeric-suffixes --additional-suffix=.txt file.txt file
>>> wc --lines file??.txt
1000 file00.txt
1000 file01.txt
325 file02.txt
2325 total

Via SO.