Which country is the largest island country in the world?

Indonesia, in fact, this issue has always been controversial. There is a joke that Australians have no sense of belonging and don't know whether they live on the largest island or the smallest continent. In fact, the concept of island and continent is very simple geographically. At present, it is common to regard Australia as the smallest continent, mainly because Australia belongs to the Oceania plate and Asia belongs to the Eurasia plate. Geographically, they don't belong to the same plate, and there are great differences in culture, so Australia is the smallest continent alone. The largest island in the world is Greenland, which belongs to Denmark, but Denmark belongs to the European continent, so Denmark cannot be regarded as an island country. Indonesia is the country with the largest number of islands in the world, consisting of 17508 large and small islands, with a land area of 1904443 square kilometers. Madagascar is the fourth largest island in the world with a total area of 627,000 square kilometers. In this way, Indonesia should be the largest island country.