Yes https://github.com/2600hz/kazoo/blob/master/applications/crossbar/doc/phone_numbers.md
or https://docs.2600hz.com/supported/applications/crossbar/doc/phone_numbers/
/v2/phone_numbers?prefix={PREFIX}&quantity={QUANTITY}&offset={OFFSET}&country={COUNTRY} should return numbers, and their status. Don't know if it shows who it is assigned to. Worst case, you could loop through accounts and use GET /v2/accounts/{ACCOUNT_ID}/phone_numbers
Someone might know a better method, or you can look at how the number manager in monsterui does it.