The calculated distance (air line) between Tillabéri and Gorom-Gorom is approximately 114 miles respectively 184 kilometers.
By car or train, the actual journey to Gorom-Gorom is certainly longer, as only the direct route (as the crow flies) between Tillabéri and Gorom-Gorom has been calculated here.
Air line (approximately)
184 kilometers
99 nautical miles