Megameter
A megameter (Mm) is a unit of length in the metric system, equal to 1 million meters (1 Mm = 10⁶ meters or 1,000 kilometers). Megameters are used to measure very large distances, typically on a global or planetary scale. For example, the Earth’s diameter is about 12.7 megameters. Although it’s a valid metric unit, the megameter is rarely used in everyday life or science, as kilometers or other astronomical units are more common for such distances.
Russian Archin
The archin (also spelled arshin) is a traditional Russian unit of length that was widely used before the adoption of the metric system. It is approximately equal to 28 inches or 0.7112 meters.
The archin was commonly used in measuring cloth, land, and building dimensions in Russia and neighboring regions. It roughly corresponds to the length of a forearm from the elbow to the tip of the middle finger, similar to the cubit.
Though obsolete today, the archin remains an important part of Russian historical measurements and appears in older legal and trade documents.
Summary:
1 archin ≈ 28 inches (0.7112 meters)
Used historically in Russia for textiles and land measurement
Based on the length of the forearm
Mostly of historical and cultural interest today
No conversions available for length.