It depends. If the serial number reads the same from back to front (eg. 0208020) it is referred to as a "radar" note, referring to how the radio waves are sent out of whatever is giving out these radio waves, and they echo back when the waves hit an object. There are also "repeater" notes, which repeat the serial number (eg. 6012601).
EDIT: Your note seems to be in Very Fine condition, worth $65. A photo would be appreciated.