Asia in both categories). At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20.4% of its total land area. With 1.2 billion people as of 2016, it accounts for about 16% of the world's human population. The continent is surrounded by the Mediterranean Sea to the north, both the Suez Canal and the Red Sea along the Sinai Peninsula to the northeast, the Indian Ocean to the southeast and the Atlantic Ocean to the west. The continent includes Madagascar and various archipelagos. It contains 54 fully recognised sovereign states (countries), nine territories and two de facto independent states with limited or no recognition. The majority of the continent and its countries are in the Northern Hemisphere, with a substantial portion and number of countries in the Southern Hemisphere.
Africa's average population is the youngest amongst all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Algeria is Africa's largest country by area, and Nigeria is its largest by population. Africa is the only continent to stretch from the northern temperate to southern temperate zones.
Africa is part of Continents Seven, a series of 7 different solo open water swims that is completed in all of the seven continents of Planet Earth either (1) within one year, or (2) over the course of one's career. The 7 different open water swims must be performed on all the world's main continuous expanses of land: Africa, Antarctica, Asia, Australia (or Oceania), Europe, North America, and South America.