We report on an analysis of X- and \gamma -ray observations of PKS 1830 - 211 , based on the long-term campaigns carried out by INTEGRAL and COMPTEL .
The INTEGRAL data currently available present a 33 \sigma significance detection in the 20 - 100 keV band , while the COMPTEL 6 -years data provide a 5.2 \sigma significance detection in the 1 - 3 MeV energy band .
At hard X-rays , INTEGRAL and supplementary SWIFT observations show flux variability on timescales of months .
At \gamma -rays , the source shows persistent emission over years .
The hard X-ray spectrum is well represented by a power-law model , with \Gamma \sim 1.3 in the 20 - 250 keV band .
This photon index is well consistent with the previous report of \Gamma \sim 1.3 obtained at E > 3.5 keV from the best fit of XMM-Newton data with a broken power law model .
The joint XMM-Newton / INTEGRAL spectrum presented here is then fit with a broken power-law model and the parameters are refined compared to the previous .
The results show the photon index changes from \sim 1.0 to \sim 1.3 at a break energy \sim 4 keV .
At MeV energies , the spectrum softens to \Gamma \sim 2.2 .
These results , together with the EGRET measurement at E \geq 100 MeV , constitute a broad-band spectrum containing the peak of the power output at MeV energies , similar to most high-luminosity \gamma -ray blazars .
The measured spectral characterstics are then discussed in the framework of the gravitational lens effects .