65537 is the largest known Fermat prime, and the 65537-gon is therefore a constructible polygon
using compass and straightedge,
as proved by Gauss. The 65537-gon has so many sides that it is, for all intents and
purposes, indistinguishable from a circle using any reasonable
printing or display methods.
Hermes spent 10 years on the construction of the 65537-gon at Königsberg around 1900. After the Second World War, his manuscripts were moved to the Mathematical Institute in Göttingen, where they can now be viewed (Coxeter 1969).