  Pulsations from the high mass X-ray binary AXJ1910.7+0917 were discovered
during Chandra observations performed in 2011 (Israel et al. 2016). We report
here more details on this discovery and discuss the source nature. The period
of the X-ray signal is P=36200+/-110s, with a pulsed fraction, PF, of 63+/-4%.
Given the association with a massive B-type companion star, we ascribe this
long periodicity to the rotation of the neutron star, making AXJ1910.7+0917 the
slowest known X-ray pulsar. We report also on the spectroscopy of XMM-Newton
observations that serendipitously covered the source field, resulting in an
highly absorbed (column density almost reaching 1e23cm-2), power law X-ray
spectrum. The X-ray flux is variable on a timescale of years, spanning a
dynamic range >60. The very long neutron star spin period can be explained
within a quasi-spherical settling accretion model, that applies to low
luminosity, wind-fed, X-ray pulsars.
