The calculated distance (air line) between Prejmer and Piatra Neamţ is approximately 87 miles respectively 140 kilometers.
By car or train, the actual journey to Piatra Neamţ is certainly longer, as only the direct route (as the crow flies) between Prejmer and Piatra Neamţ has been calculated here.
Air line (approximately)
140 kilometers
76 nautical miles