  We build a comprehensive sample to statistically describe the properties of
X-ray flashes (XRFs) and X-ray riches (XRRs) from the latest third Swift Burst
Alert Telescope (BAT3) catalog of Gamma-ray bursts (GRBs). We obtain 81 XRFs,
540 XRRs, and 394 classical GRBs (C-GRBs). We statistically explore the
different properties of the $\gamma$-ray prompt emission, the X-ray emission,
the X-ray lightcurve type, the association with supernovae (SNe), and the host
galaxy properties for these sources. We confirm that most XRFs/XRRs are long
GRBs with low values of peak energy $E^{obs}_{peak}$ and they are
low-luminosity GRBs. XRFs, XRRs, and C-GRBs follow the same
$E_{X,iso}$-$E_{\gamma,iso}$-$E_{peak,z}$ correlations. Compared to the
classical GRBs, XRFs are favorable to have the association with SN explosions.
We do not find any significant differences of redshift distribution and host
galaxy properties among XRFs, XRRs, and C-GRBs. We also discuss some
observational biases and selection effects that may affect on our statistical
results. The GRB detectors with wide energy range and low energy threshold are
expected for the XRF/XRR research in the future.
