Denmark is yet another multiple-country sovereign state- Denmark (proper), Greenland, and the Faroe Islands are constituent countries of the Kingdom of Denmark.
That's not such a great example, since Greenland and the Faroe Islands are both of zero significance. (Greenland is significant geographically, but not as a political entity.)
Population of Denmark: 6 million.
Population of Greenland: 0.05 million.
Population of the Faroe Islands: 0.05 million.