The calculated distance (air line) between Düsseldorf-Pempelfort and Mülheim is approximately 14 miles respectively 23 kilometers.
By car or train, the actual journey to Mülheim is certainly longer, as only the direct route (as the crow flies) between Düsseldorf-Pempelfort and Mülheim has been calculated here.
Air line (approximately)
23 kilometers
12 nautical miles