A parody of the typical numerical pseudo-science tossed about regarding the Great Pyramid and the ‘cosmic truths’ (such as the distance from the Earth to the Sun) that the Egyptians supposedly incorporated into its measurements.
The remark about sharpening razor blades at the end of the paragraph is similarly a reference to the pseudo-scientific ‘fact’ that (small models of) pyramids are supposed to have, among many other powers, the ability to sharpen razor blades that are left underneath the pyramids overnight. There’s another more explicit reference on p. 140/134: “[…] contrary to popular opinion pyramids don’t sharpen razor blades”.