  The prompt photon production in hadronic collisions has a long history of
providing information on the substructure of hadrons and testing the
perturbative techniques of QCD. Some valuable information about the parton
densities in the nucleon and nuclei, especially of the gluon, can also be
achieved by analysing the measurements of the prompt photon production cross
section whether inclusively or in association with heavy quarks or jets. In
this work, we present predictions for the inclusive isolated prompt photon
production in $ pp $ collisions at center-of-mass energy of 13 TeV using
various modern PDF sets. The calculations are presented both as a function of
photon transverse energy $ E_\textrm{T}^\gamma $ and pseudorapidity $
\eta^\gamma $ for the ATLAS kinematic coverage. We also study in detail the
theoretical uncertainty in the cross sections due to the variation of the
renormalization, factorization and fragmentation scales. Moreover, we introduce
and calculate the ratios of photon momenta for different rapidity regions and
study the impact of various input PDFs on such quantity.
