Which is the biggest palace in the world still in use by a head of state?

Explanation

With 608 rooms, the Stockholm Royal Palace is the biggest palace in the world still used by a head of state - King Carl XVI Gustav. The palace houses several of the greatest and most interesting sights in Stockholm - the Royal Apartments, the Hall of State, the Apartments of the Orders of Chivalry, the Treasury, the Tre Kronor Palace Museum, the Armoury and the Museum of Antiquities of Gustav III. Buckingham Palace has 775 rooms, but covers a smaller area.