171Yb has 70 protons and 101 neutrons.
171Yb is a stable isotope.
The mass excess of 171Yb is -59306.818 with an uncertainty of ±0.013.
The mass was measured using a Penning Trap and the related equations include:
Influence Equations
100% 171Yb-129Xe1.326 1
Reference
1. R. Rana, M. Hocker, E.G. Myers (2012) Atomic masses of strontium and ytterbium
Physical Review A 86(5)
https://journals.aps.org/pra/abstract/10.1103/PhysRevA.86.050502