  The anisotropy of pressure arises due to the various complex phenomena that
happen inside the neutron star (NS). In this study, we calculate the degree of
anisotropy inside the NS using the scalar pressure anisotropy model.
Macroscopic properties such as mass, radius, compactness, redshift, tidal
deformability, the moment of inertia, and surface curvature (SC) are computed
for the anisotropic NS with the equation of states spanning from relativistic
to nonrelativistic cases. The variation of SC as the functions of the
above-mentioned quantities are computed by changing the degree of anisotropy.
Pressure anisotropy has significant effects on the magnitude of SC. The
universal relations between the canonical SC$-\Lambda$ and SC$-\bar{I}$ are
studied. From the GW170817 tidal deformability data constraints on SC are found
to be SC$_{1.4}(10^{14}) = 3.44_{-1.0}^{+0.4}, 2.85_{-1.20}^{+0.62}, \ {\rm
and} \ 2.52_{-1.02}^{+0.61}$ for $\lambda_{\rm BL} = 0.0, 1.0$, and $2.0$
respectively.
