Top quark properties and mass measurements with ATLAS

The top quark plays a unique role among other known quarks as it decays before it forms hadronic bound states. Thus, studying its properties provides an interesting opportunity to access properties of a bare quark directly. The latest measurements of these properties with the ATLAS detector at the LHC are presented. Measurements sensitive to the Wtb vertex are summarized and compared to the best theoretical calculations. Effects of colour reconnection on the jet variables in top quark events are presented. Limits on the flavour-changing neutral currents are discussed. The latest top quark decay width and mass measurements are reported.