Amusingly, the cell is about halfway between the radius of the observable universe (4.4 * 10^26 meters) and Planck length (1.6 * 10^-35 meters), at between 10^-4 and 10^-5 meters, or 0.1mm and 0.01mm.
About the size of a eukaryotic cell, in particular.
You seem to be abusing exponential notation there. Halfway between 0 and 4.4 * 10^26 is 2.2 * 10^26, quite a bit larger than a cell. Halfway from Planck length should be just about the same given it's indistinguishable from 0 on that large of a scale. Even if you wanted to use logarithmic scaling, half of 4.4 * 10^26 would 4.4 * 10^13. Negative exponents are fractional. The Planck length isn't actually a negative number.
>Even if you wanted to use logarithmic scaling, half of 4.4 * 10^26 would 4.4 * 10^13
That's the geometric mean of 4.4 * 10^26 and 1. He took the geometric mean of the radius of the observable universe and the Planck length. That's a reasonable way to define "halfway" across orders of magnitude