Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE program ( program_id number, name text, origin text, launch number, owner text )
TABLE: CREATE TABLE broadcast ( channel_id number, program_id number, time_of_day text )
TABLE: CREATE TABLE channel ( channel_id number, name text, owner text, share_in_percent number, rating_in_percent number )
TABLE: CREATE TABLE broadcast_share ( channel_id number, program_id number, date text, share_in_percent number )

### Question ###
what is the number of different channel owners?

### Accurate SQL ###

SELECT COUNT(DISTINCT owner) FROM channel