Five main islands and 30 smaller archipelagoes are home to the majority of the population. The main islands are Sumatra (473,606 sq km), Kalimantan (1539,400 sq km), Sulawesi (189,216 sq km), Irian Jaya (421,981 sq km) and last but not least Java (132,187 sq km), home to 70 percent of the country's population. Indonesia shares Irian Jaya with Papua New Guinea and two thirds of the island of Kalimantan with Malaysia and Borneo.
The islands and people of Indonesia constitute the fourth most populated nation in the worlds. As a democratic republic, Indonesia is divided into 26 provinces and special territories and classified geographically into four groups. First are the Greater Sundas, made up of the larger islands of Sumatra, Java, Kalimantan and Sulawesi. Second are the Lesser Sundas, consisting of smaller islands from Bali eastward to Timor, Third is Maluku which includes all the islands between Sulawesi and Irian Jaya. The fourth and the final group is Irian Jaya in the extreme of eastern part of the country.