Is "several, some, most, many, all" are adjective of no. or adjective of quantity?

The best way to know the type of an adjective is to see how it is used in that particular sentence.
The words you have written are indefinite adjectives of number.
For example: Some boys were playing in the park.
Several boys were playing in the park.
All boys were playing in the park.
Many boys were playing in the park.
Most boys were playing in the park.
They all mark a noun(boy) which is a countable noun. So, they are adjectives of number.

But, if used differently, 'some' can be an adjective of quantity. For example: Can I have some tea please?