  We present results of investigation of the poorly studied X-ray pulsar Swift
J1816.7--1613 during its transition from the type I outburst to the quiescent
state. Our studies are based on the data obtained from X-ray observatories
\textit{Swift}, \textit{NuSTAR} and \textit{Chandra} alongside with the latest
IR data from UKIDSS/GPS and \textit{Spitzer}/GLIMPSE surveys. The aim of the
work is to determine parameters of the system: the strength of the neutron star
magnetic field and the distance to the source, which are required for the
interpretation of the source behaviour in the framework of physically motivated
models. No cyclotron absorption line was detected in the broad-band energy
spectrum. However, the timing analysis hints at the typical for the X-ray
pulsars magnetic field from a few $\times 10^{11}$ to a few $\times 10^{12}$ G.
We also estimated type of the IR-companion as a B0-2e star located at distance
of 7--13~kpc.
