An adjective has the type cardinal adjective if it has a numeric value (apart from the value one all values of positive integers). This criterion is necessary and sufficient.
Given X an adjective: If X has numeric value (apart from the value one all values of positive integers), then X has the type cardinal.
There are constraints concerning the selection of the determiner: only the definite article, the possessive determiner or the demonstrative determiner can precede the cardinal adjective in a noun phrase. We consider that, for cardinal adjective, the features number and gender do not apply. The noun specified by a cardinal adjective has to realise the number value plural.
Given Art an article, Det a determiner, indf indefinite value, N a noun, NP a noun phrase: If NP (Art/indf + X + N), or NP (Det/indf + X + N) fails, then X is a cardinal adjective.