CREATE TABLE table_71936 ("City" TEXT, "Hanzi" TEXT, "Hanyu Pinyin" TEXT, "Regional Population ( 2010 ) " TEXT, "GDP ( 2011 )  ( billion yuan ) " FLOAT)

Which Hanzi has a Regional Population of 4,591,972 in 2010?
SELECT "Hanzi" FROM table_71936 WHERE "Regional Population(2010)" = '4,591,972'
SELECT "Hanzi" FROM "table_71936" WHERE "Regional Population(2010)" = '4,591,972'