The global properties of the final states produced in hadronic interactions of protons at centre-of-mass energies of future hadron colliders (such as FCC-hh at CERN, and SppC in China), are studied. The predictions of various Monte Carlo (MC) event generators used in collider physics (pythia 6, pythia 8, and phojet) and in ultrahigh-energy cosmic-rays studies (epos, and qgsjet) are compared. Despite their different underlying modeling of hadronic interactions, their predictions for proton-proton (p-p) collisions at s√=100 TeV are quite similar. The average of all MC predictions (except phojet) for the different observables are: (i) p-p inelastic cross sections σinel = 105 ± 2 mb; (ii) total charged multiplicity Nch = 150 ± 20; (iii) charged particle pseudorapidity density at midrapidity dNch/dη|η=0 = 9.6 ± 0.2; (iv) energy density at midrapidity dE/dη|η=0 = 13.6 ± 1.5 GeV, and dE/dη|η=5 = 670 ± 70 GeV at the edge of the central region; and (v) average transverse momenta at midrapidities 〈pT〉 = 0.76 ± 0.07 GeV/c. At midrapidity, epos and qgsjet-ii predict larger per-event multiplicity probabilities at very low (Nch < 3) and very h ... mehrigh (Nch > 100) particle multiplicities, whereas pythia 6 and 8 feature higher yields in the intermediate region Nch ≈ 30–80. These results provide useful information for the estimation of the detector occupancies and energy deposits from pileup collisions at the expected large FCC-hh/SppC luminosities.