  We examine the effects of massive primordial black holes (PBHs) on cosmic
structure formation, employing both a semi-analytical approach and cosmological
simulations. Our simulations incorporate PBHs with a monochromatic mass
distribution centered around $10^6 \ \rm M_{\odot}$, constituting a fraction of
$10^{-2}$ to $10^{-4}$ of the dark matter (DM) in the universe, with the
remainder being collision-less particle dark matter (PDM). Additionally, we
conduct a $\Lambda$CDM simulation for comparative analysis with runs that
include PBHs. At smaller scales, halos containing PBHs exhibit similar density
and velocity dispersion profiles to those without PBHs. Conversely, at larger
scales, PBHs can expedite the formation of massive halos and reside at their
centers due to the `seed effect'. To analyze the relative distribution of PBH
host halos compared to non-PBH halos, we apply nearest-neighbor (NN)
statistics. Our results suggest that PBH host halos, through gravitational
influence, significantly impact the structure formation process, compared to
the $\Lambda$CDM case, by attracting and engulfing nearby newly-formed
minihalos. Should PBHs constitute a fraction of DM significantly larger than
$\sim$$10^{-3}$, almost all newly-formed halos will be absorbed by PBH-seeded
halos. Consequently, our simulations predict a bimodal feature in the halo mass
function, with most of the massive halos containing at least one PBH at their
core and the rest being less massive non-PBH halos.
