According to the sources I've checked, only numbers from 1 to 4 have an animate ending (meaning that the accusative case will be the same as the genitive, endingwise). Numbers from 5 upward will have a common accusative for both animate and inanimate nouns.
However, in compound numerals, all components decline... what if I want to decline a number like 21, 22?
Since 1 and 2 also have an agreement in gender, will 1 and 2 decline as animate numerals, whereas "20" declines the usual way?
Example: What would be an animate accusative of двадцать одна (admitting that the agreement in gender happens)? Двадцать одну?
And двадцать один? Does it become двадцать одного?