The earth is a planet on which we live. It is the fifth largest planet and distanced third from the sun. The estimated total surface area of the Earth is 510,100,448 sq. Km., of which the sea or hydrosphere covers five-sevenths or more accurately, 70.78% (361,059,266 sq. Km.)and the land or lithosphere, two-sevenths or 29.22% (149.041,182 sq.Km.).
It has a mass 6.58*1021 tons (esimated). Its density is 5.515 times that of water (or 5.517 kg/litre). The polar diameter is 12,712 kms and the equatorial diametre is 12,755 kms. Likewise, the equatorial circumference of the earth is 40,076 km. with a polar or meridianal circumference of 40,008 km. indicating that the earth is not a true sphere but an ellipsoid, flattened at the poles. The earth also has a slight ellipticity at the equator.
Most populous country: The largest population of any country is that of China, which has massive share of the world's population--about 25%. The rate of natural increase in population in the People's Republic of China is now estimated to be 37,000 a day or 13.6 million per year in mid-2001, the population of china was estimated to be 1.56 billion.
Least populous country: The independent State with the smallest population is the Vatican City or the Holy See, with 900 inhabitants (est. mid-2001).
Most densely populated: The most densely populated country in the world is Monaco with 15,946.5 people per sq. km. in 2001.
Number of Countries: The world comprises of 192 Sovereign States, 189 members of The United Nations and three non-members, viz., China (Taiwan), Switzerland & Vatican City. There are 61 non-sovereign and 6 disputed territories or other territories (dependencies of sovereign states, territories claimed in Antarctica and disputed territories), making a total of 259.
Lagest country: The country with the greatest area is Russia, with a total area of 17,075,200 sq. km. or 11.5% of the world's total land area. It is 70 times larger than U.K. in area, but with a population of 148 million in mid 2001, has only 2.4 times more people than the U.K.
Smallest country: The smallest independent country in the world is the State of the Vatican City or Holy See, which was made an enclave within the city of Rome, Italy on February 11, 1929. The enclave have an area of 0.44 sq.km.
Smallest Republic: The world's smallest republic is Nauru, less than one degree south of the equator in the Western Pacific, which became independent on January 31, 1968. It has an area of 21 sq.km. and a population of 11,900 in mid-2001.
Smallest Colony: The smallest colony in the world is Gibraltar (since 1969, the city of Gibraltar), with an area of 5.8 sq. km. Pitcairn Island, the only inhabited (55 people in late-1993) island of a group of four (total area 4 sq. km.)has an area of 388 hectares (960 acres).
Most populous city: The most populous urban agglomeration in the world is Tokyo, which was listed in the United Nations Prospectus of World Urbanisation 1992 as having a population of 25,000,000. It rose to 26,450,000 by mid 2001.
Largest city: The world's largest city, in area, is Mount Isa, Queensland, Australia , which has an administered area of 41,225 square kilometres.
Highest Capital: The highest capital in the world, before the domination of Tibet by China, was Lhasa, at an elevation of 3.684 metres above sea level. La Paz, the administrative and de facto capital of bolivia, stands at an altitude of 3.631 metres above sea level.
Highest Town: Wenchuan, the new town founded in 1955 on the Chingai-Tibet road, located north of the Tangla range in China at 5,100 metres above sea level, is the highest town in the world.
Least Populous Town: China, the world's most populous country, has what may be the world's least populous town, Yumen, in the remote Himalayan region of Tibet, has only three residents, an elderly father and his two daughters. The town has a township Government, an administrative head, an official seal and an emblem. The father, Sangpu, 72, has retired as the town head and has been succeeded by his elder daughter Zhuoga. The remote town lies 550 kms. southeast of the capital Lhasa. Dozens of families ance lived in Yumen, but slowly they all moved away. By 1989, only Sagpu'sfamily was left.