Reversing a Number

CREATE OR REPLACE FUNCTION reverse_number(n INTEGER)
RETURNS INTEGER AS $$
DECLARE
	reversed_str TEXT := '';
	digit CHAR;
	n_str TEXT;
BEGIN
	n_str := n::TEXT;

	FOR i IN REVERSE LENGTH(n_str)..1 LOOP
		reversed_str := reversed_str || SUBSTRING(n_str, i, 1);
	END LOOP;


	RETURN reversed_str::INTEGER;
END;
$$ LANGUAGE plpgsql;