  A detailed analysis of new and existing photometric, spectroscopic and
spatial distribution data of the eccentric binary V731 Cep was performed.
Spectroscopic orbital elements of the system were obtained by means of
cross-correlation technique. According to the solution of radial velocities
with UBVRcIc light curves, V731 Cep consists of two main-sequence stars with
masses M$_{1}$=2.577 (0.098) M$_{\odot}$, M$_{2}$=2.017 (0.084) M$_{\odot}$,
radii R$_{1}$=1.823 (0.030) R$_{\odot}$, R$_{2}$=1.717 (0.025) R$_{\odot}$, and
temperatures T$_{eff1}$=10700 (200) K, T$_{eff2}$=9265 (220) K separated from
each other by a=23.27 (0.29) R$_{\odot}$ in an orbit with inclination of
88$^{\circ}$.70 (0.03). Analysis of the O--C residuals yielded a rather long
apsidal motion period of U=10000(2500) yr compared to the observational history
of the system. The relativistic contribution to the observed rates of apsidal
motion for V731 Cep is significant (76%). The combination of the absolute
dimensions and the apsidal motion properties of the system yielded consistent
observed internal structure parameter (log$\bar{k}_{2,obs}$=-2.36) compared to
the theory (log$\bar{k}_{2,theo}$=-2.32). Evolutionary investigation of the
binary by two methods (Bayesian and evolutionary tracks) shows that the system
is t=133(26) Myr old and has a metallicity of [M/H]=-0.04(0.02) dex. The
similarities in the spatial distribution and evolutionary properties of V731
Cep with the nearby ($\rho\sim3^{\circ}$.9) open cluster NGC 7762 suggests that
V731 Cep could have been evaporated from NGC 7762.
