Cartman, I think you have quoted an assembly number, not the serial number. Assembly numbers are often stamped on the frame under the crane, it was a number for keeping track of parts at the factory. The serial number should be on the underside of the grip frame, you may have to take off the grips to see it.
If it is a prewar K22 Outdoorsman then the serial number range is 632132 to 682419. If it is a prewar K22 Masterpiece then the serial number range is 682420 to 696952.
If it is a post war K22 Masterpiece then it should have a K prefix to the serial number.
If it is a post 1957 Model 17 it should have a K prefix or within the serial number and have model 17 stamped under the crane on the frame.