  Here we present an initial look at the dynamics and stability of 178
multiplanetary systems which are already confirmed and listed in the NASA
Exoplanet Archive. To distinguish between the chaotic and regular nature of a
system, the value of the MEGNO indicator for each system was determined. Almost
three-quarters of them could be labelled as long-term stable. Only 45 studied
systems show chaotic behaviour. We consequently investigated the effects of the
number of planets and their parameters on the system stability. A comparison of
results obtained using the MEGNO indicator and machine-learning algorithm SPOCK
suggests that the SPOCK could be used as an effective tool for reviewing the
stability of multiplanetary systems. A similar study was already published by
Laskar and Petit in 2017. We compared their analysis based on the AMD criterion
with our results. The possible discrepancies are discussed.
