The below SQL report will return all the default queue owners of all your helpdesk desk categories along with the settings.

SELECT 
 USER.FULL_NAME AS OWNER_NAME,
 USER.EMAIL,
 HC.NAME AS QUEUE_NAME,
 HC.ORDINAL,
 HC.DEFAULT_OWNER_ID,
 HC.CC_LIST,
 HC.USER_SETTABLE,
 HC.HD_QUEUE_ID
FROM
 HD_CATEGORY HC
 LEFT JOIN
 USER ON HC.DEFAULT_OWNER_ID = USER.ID
ORDER BY HC.HD_QUEUE_ID

And the results look like the below