The calculated distance (air line) between Ust’-Ordynskiy and Irkutsk is approximately 40 miles respectively 64 kilometers.
By car or train, the actual journey to Irkutsk is certainly longer, as only the direct route (as the crow flies) between Ust’-Ordynskiy and Irkutsk has been calculated here.
Air line (approximately)
64 kilometers
35 nautical miles