It is known that 1 m is equal to 100 cm and that 1 km is also equal to 1000 m. Thus, the conversion may be done by the dimensional analysis and the use of proper conversion factors.
(86000 cm) x (1 m/ 100 cm) x (1 km / 1000 m) = 0.86 km
Therefore, the answer is 0.86 km.