A measurement of the top quark–antiquark pair production cross section ({\sigma }{t\overline{t}}) in proton–proton collisions at a centre-of-mass energy of 13 (\phantom{\rule{0.166667em}{0ex}}\text{Te}\phantom{\rule{0.333333em}{0ex}}) is presented. The data correspond to an integrated luminosity of (35.9\phantom{\rule{0.166667em}{0ex}}{\text{fb}}^{-1}), recorded by the CMS experiment at the CERN LHC in 2016. Dilepton events ( (e) ({}^{±}) (\mu ) ({}^{\mp }), ({\mu }^{+}{\mu }^{-}), ({e}^{+}{e}^{-}) ) are selected and the cross section is measured from a likelihood fit. For a top quark mass parameter in the simulation of ({m}{t}^{\mathrm{MC}}=172.5\phantom{\rule{0.166667em}{0ex}}\text{Ge}\phantom{\rule{0.333333em}{0ex}}) the fit yields a measured cross section ({\sigma }{t\overline{t}}=803±2\phantom{\rule{0.166667em}{0ex}}\text{(stat)}±25\phantom{\rule{0.166667em}{0ex}}\text{(syst)}±20\phantom{\rule{0.166667em}{0ex}}\text{(lumi)}\phantom{\rule{0.166667em}{0ex}}\text{pb}), in agreement with the expectation from the standard model calculation at next-to-next-to-leading order. A simultaneous fit of the cross section and the top quark mass parameter in the powheg simulation is performed. The measured value of ({m}{t}^{\mathrm{MC}}=172.33±0.14\phantom{\rule{0.166667em}{0ex}}\text{(stat)}{\phantom{\rule{0.166667em}{0ex}}}_{-0.72}^{+0.66}\phantom{\rule{0.166667em}{0ex}}\text{(syst)}\phantom{\rule{0.166667em}{0ex}}\text{Ge}\phantom{\rule{0.333333em}{0ex}}) is in good agreement with previous measurements. The resulting cross section is used, together with the theoretical prediction, to determine the top quark mass and to extract a value of the strong coupling constant with different sets of parton distribution functions.