No, "one" is not a common noun. It is a numeral, specifically a cardinal number.

Here's why:

* Common nouns are general names for people, places, or things (e.g., dog, city, book).

* Numerals represent numbers or quantities. They don't name specific things, but rather indicate how many.

While "one" can sometimes be used as a pronoun (e.g., "One of us must go"), its primary function is as a numeral.