Estonia is a developed country, with a high-income advanced economy; ranking very high in the Human Development Index. The sovereign state is a democratic unitary parliamentary republic divided into fifteen counties. It has a population of 1.3 million, and is one of the least populous members of the European Union, the Eurozone, the OECD, the Schengen Area, NATO, and the United Nations Security Council. Estonia has consistently ranked highly in international rankings for quality of life, education, digitalization of public services and the prevalence of technology companies.