The formula with 2.2 substituted
miles = 2.2 ÷ 1.609344 = 1.367
The constant is an exact definition, not a rounded factor: the mile is 1.609344 km, the US gallon is 3.785411784 litres and the imperial gallon is 4.54609 litres. The Kilometres to Miles Converter explains where each comes from and gives a longer table.
At a walking pace of 5 km/h, 2.2 km takes about 26 minutes. At an easy running pace of 10 km/h it takes about 13. In metres it is 2,200.
What 2.2 kilometres means in practice
2.2 km comes out at 1.37 miles. It is a little over half of a 5K, and a common warm-up distance before an interval session on a running track: five and a half laps.