  The comparative analysis of parameters is carried out for two samples of
radio pulsars. Objects of the first sample have periods P > 2 sec, the second
is characterized by magnetic fields at the neutron star surface $Bs >
4.4\times10^{13}$ G. The main goal of this analysis is to find some differences
between normal pulsars and anomalous X-ray pulsars (AXP) and soft gamma-ray
repeaters (SGR) with the similar values of periods and magnetic fields. It is
shown that the dependence of period derivatives on periods for pulsars with
long periods is $dP/dt \propto P^{1.67}$. This means that we must search for
another braking mechanism differing from the magnetic dipole one which gives
$dP/dt \propto P^{-1}$ or use some specific distributions of parameters. On the
other hand, radio pulsars with strong magnetic fields and AXP/SGR can be
described by the magnetic dipole model. Radio pulsars with P > 2 sec have ages
on average two orders of magnitude higher than objects with $Bs > 4.4 \times
10^{13}$ G and are located much higher above the Galactic plane. The obtained
results show that the main feature of AXP/SGR is the strong magnetic field and
not the large period.
