Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_13836704_6 (rank VARCHAR, freight___metric_tonnes__ VARCHAR)
### Question:
What is the rank of the airport with a  freight ( metric tonnes ) of 23791?
### Answer:
SELECT rank FROM table_13836704_6 WHERE freight___metric_tonnes__ = 23791