truncated incorrect INTEGER VALUE : 'EN_US'

Question

got this error when I tried to create a table 'top20bypopulation' from a select statement

query :

CREATE table top20bypopulation as
SELECT Name,format(Population,'EN_US') as population FROM country
ORDER BY Population DESC
LIMIT 20;

error :
truncated incorrect INTEGER VALUE : 'EN_US'
But the SELECT runs okey, but when I create table out of it, it gives this error.
I am new to this language, someone please answer how to achieve this.