It is easier and more readable to use the direct numbers (note that you want to use 161 in the range()
call, since the last number is not included):
import os
for count in range (16, 161):
os.makedirs("C:\\Users\joshuarb\Desktop\Organized_Images\IMG_{:04d}".format(count))
Also notice that I used a zero-padding with width 4, since your naming convention differs for IMG_0016 and IMG_00160 so I chose to limit to DOS' usual 8-character. Adjust according to your needs.