In an email a friend of mine wrote to me:
I got a couple of books from a friend on math and what not.
Can anyone please tell me what does what not mean here? If there is any meaning.
Looks like your friend has inserted a space in whatnot, as you have done in anyone.
From Collins dictionary:
People sometimes say 'and whatnot' or 'or whatnot' after mentioning one or more things, to refer in a vague way to other things which are similar. (informal, spoken, vagueness) ⇒ "The women were there in their jeans and T-shirts and overalls and whatnot." ⇒ "The council can send messages or letters or whatnot in Spanish."