Id value in dump file exceeds the number of atoms

Hi all.
When I use this command

dump 1 all custom 10000 dump.lammpstrj id mol type mass x y z

I checked the dump.lammpstrj. In the file, the NUMBER OF ATOMS is 170000. There are many lines with id>170000. e.g.

174451 3898 1 1.008 259.288 265.278 210.855
15243 341 1 1.008 264.16 262.99 205.423
174423 3898 2 12.011 259.262 265.59 211.959
174452 3898 1 1.008 261.275 266.294 211.86
18434 412 1 1.008 259.921 262.954 204.823
108256 2419 1 1.008 264.246 265.911 204.295
18423 412 2 12.011 258.82 262.895 204.917
108255 2419 1 1.008 266.408 267.061 204.172
15217 341 2 12.011 265.297 263.88 207.222
15244 341 1 1.008 266.1 263.406 207.792
15218 341 3 15.999 265.911 264.894 206.385
178024 3978 1 1.008 265.58 267.459 211.238
178023 3978 1 1.008 264.711 268.945 209.673
15245 341 1 1.008 265.22 265.411 206.063
178026 3978 1 1.008 268.019 266.864 211.297
106041 2370 2 12.011 269.929 263.04 205.572
106066 2370 1 1.008 268.223 264 206.581
106040 2370 2 12.011 269.334 263.911 206.712
178025 3978 1 1.008 266.981 266.434 209.893
177999 3978 2 12.011 267.361 267.242 210.54

Why this happens? Could anyone help me?

the input file is:


units		real
atom_style	full
neighbor	2.0 bin
neigh_modify	every 1 delay 0 check no

read_data	reax.data

pair_style	reax/c lmp_control
pair_coeff * * ffield2016.reax.cho H C O

timestep	0.25
thermo 100
thermo_modify flush yes

fix		        1 all npt temp 300 300 25 iso 0.0 0.0 250
fix             2 all qeq/reax 1 0.0 10.0 1e-6 param.qeq

fix 4 all reax/c/species 1 1 10000 species.out
dump 1 all custom 10000 dump.lammpstrj id mol type mass x y z

run		200000

unfix 1 
fix		1 all npt temp 300 300 100 y 0.0 0.0 1000 z 0.0 0.0 1000
fix		2 all deform 10000 x scale 2.0 remap v
 
thermo_style custom step temp pxx
thermo_modify flush yes
 
run 1000000

This is quite valid. The atom ID is supposed to uniquely identify atoms over the entire simulation. So if at some point atoms are deleted, the will be atom IDs with values larger than the number of atoms. Similarly, atom IDs will be read as is from a data file.

thanks for your quick reply.