Sorry about the Hydrogen part above since I went along with that one.

[A typical neutron star has a mass between 1.35 and about 2.1 solar masses, with a corresponding radius of about 12 km if the Akmal-Pandharipande-Ravenhall (APR) Equation of state (EOS) is used.[1][2] In contrast, the Sun's radius is about 60,000 times that. Neutron stars have overall densities predicted by the APR EOS of 3.7 to 5.9 × 1017 kg/m³ (2.6 to 4.1 × 1014 times Solar density),[3] which compares with the approximate density of an atomic nucleus of 3 × 1017 kg/m³.[4] The neutron star's density varies from below 1 × 109 kg/m³ in the crust increasing with depth to above 6 or 8 × 1017 kg/m³ deeper inside.[5]. This is approximately the weight of the entire human population condensed into the size of a sugar cube.]

http://en.wikipedia.org/wiki/Neutron_star

It doesn't hurt:
Pauli Exclusion Principle and Electro Magnetic Dipole Moment. (From link above.)

Of course, it seems to vary.