The calculated distance (air line) between Hainburg an der Donau and Geidorf is approximately 101 miles respectively 163 kilometers.
By car or train, the actual journey to Geidorf is certainly longer, as only the direct route (as the crow flies) between Hainburg an der Donau and Geidorf has been calculated here.
Air line (approximately)
163 kilometers
88 nautical miles