The Mass of a Neutron is 1.00866491588 u. This equals:
The neutron is a subatomic hadron particle that has the symbol n or n0. Neutrons have no net electric charge and a mass slightly larger than that of a proton. With the exception of hydrogen-1, the nucleus of every atom consists of at least one neutron as well as one or more protons. This constant is specified with a standard uncertainty (standard deviation) of: 0.000 000 074 E-27 kg
A neutron decays into a proton, electron and anti-neutrino via Beta decay (weak nuclear force).