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 table_20568 ( "Year" real, "GDP Nominal ($ billions)" text, "GDP Adjusted ($ billions)" text, "Population (millions)" text, "GDP per capita Nominal ($)" real, "GDP per capita Adjusted ($)" real )

### Question ###
What is the population in millions when the adjusted GDP is 492 billion?

### Accurate SQL ###

SELECT "Population (millions)" FROM table_20568 WHERE "GDP Adjusted ($ billions)" = '492'