In "Word Watch," Anne H. Soukhanov of "The American Heritage Dictionary" cited some examples of "a class of English words, usually informal or slang, that are wholly or partly numerals," but ignorance or reticence kept her list short. Here are more for Word Ways readers to come up with. Answers can be found in Answer and Solutions at the end of this issue.
Ashley, Leonard R. N.
"Numbers Functioning As Nouns,"
Word Ways: Vol. 23
, Article 20.
Available at: https://digitalcommons.butler.edu/wordways/vol23/iss3/20