Answer
$g = 6.67 \times 10^{12} ~m/s^2$
Work Step by Step
Let's use $2.0 \times 10^{30}~kg$ as the mass of the sun.
The mass of the neutron star is $10^{31}~kg$:
$g = \frac{GM}{r^2} = \frac{(6.67 \times 10^{-11} ~N \cdot m^2/kg^2)(10^{31}~kg)}{(10^4 ~m)^2}$
$g = 6.67 \times 10^{12} ~m/s^2$