  We analyse different photometric and spectroscopic properties of active
galactic nuclei (AGNs) and quasars (QSOs) selected by their mid-IR power-law
and X-ray emission from the COSMOS survey. We use a set of star-forming
galaxies as a control sample to compare with the results. We have considered
samples of obscured (HR > -0.2) and unobscured (HR < -0.2) sources including
AGNs with $L_X$ < $10^{44}$ erg s$^{-1}$, as well as QSOs ($L_X$ > $10^{44}$
erg s$^{-1}$) with 1.4 < z < 2.5. We also study the typical environment of
these samples, by assessing neighbouring galaxy number density and neighbour
properties such as colour, stellar mass and star formation rate. We find that
the UV/optical and mid-infrared colour distribution of the different AGN types
differ significantly. Also, we obtain most of AGNs and QSOs to be more compact
when compared to the sample of SF galaxies. In general we find that the stellar
mass distribution of the different AGN sample are similar, obtaining only a
difference of $\Delta\overline{\mathrm{log}M}=0.3$ dex ($M_{\odot}$) between
unobscured and obscured QSOs. Obscured and unobscured AGNs and QSOs reside in
different local environment at small ($r_p$ < 100 kpc) scales. Our results
support previous findings where AGN type correlates with environment. These
differences and those found in AGN host properties cast out the simplest
unified model in which obscuration is purely an orientation effect.
