HR: the term "mass" in Newtonian theory denotes relativistic mass.
Hp: the term "mass" in Newtonian theory denotes "real" mass.
Where m denotes mass, and r denotes a radius.
Another way to denote atomic mass is like that: the most common isotope of uranium is uranium-238 which has 92 protons, 92 electrons, and 146 neutrons.
Uncertainty values denote one standard deviation, except isotopic composition and standard atomic mass from IUPAC which use expanded uncertainties.