  Charged-particle distributions are measured in proton-proton collisions at a
centre-of-mass energy of 13 TeV, using a data sample of nearly 9 million
events, corresponding to an integrated luminosity of 170 $\mu$b$^{-1}$,
recorded by the ATLAS detector during a special Large Hadron Collider fill. The
charged-particle multiplicity, its dependence on transverse momentum and
pseudorapidity and the dependence of the mean transverse momentum on the
charged-particle multiplicity are presented. The measurements are performed
with charged particles with transverse momentum greater than 500 MeV and
absolute pseudorapidity less than 2.5, in events with at least one charged
particle satisfying these kinematic requirements. Additional measurements in a
reduced phase space with absolute pseudorapidity less than 0.8 are also
presented, in order to compare with other experiments. The results are
corrected for detector effects, presented as particle-level distributions and
are compared to the predictions of various Monte Carlo event generators.
