By the Trans-Siberian Railway, Moscow to Irkutsk is about 5185 km.
1,369.04 miles (2,203.25 kilometres)
1 nautical mile = approximately 1.151 miles.
The letter "k" is used to denote the metric prefix kilo (1000), which is a metric prefix. you would not measure miles in kilomiles. But if you were to, 50k miles would be 50,000 miles.
Exactly 40 miles. Changing from lower case to upper case does not alter the distance!