Which country has the longest continuous land border with Russia?

The border between Russia and Kazakhstan is the longest continuous land border in the world. The Kazakhstan–Russia border is the 7,644-kilometre (4,668.24 miles). The international border between the Republic of Kazakhstan and the Russian Federation is in the same location as the former administrative-territorial border between the Kazakh Soviet Socialist Republic and the Russian Soviet Federative Socialist Republic.

Kazakhstan is the world's largest landlocked country, it has a population of 18.8 million, and one of the lowest population densities in the world, at fewer than 6 people per square kilometre (15 people per sq mi).

The territory of Kazakhstan has historically been inhabited by nomadic groups and empires. Before the Russian colonisation, the Kazakhs had a highly developed culture based on their nomadic pastoral economy. Islam was introduced into the region with the arrival of the Arabs in the 8th century.

Kazakhstan has the largest and strongest performing economy in Central Asia. It has an abundant supply of accessible mineral and fossil fuel resources. Development of petroleum, natural gas, and mineral extractions has attracted most of the over $40 billion in foreign investment in Kazakhstan since 1993 and accounts for some 57% of the nation's industrial output.