Faith writes:
They are numbered so that you run across such statements as "such and such a gene on Chromosome 15," so the question is whether this sort of locatability perhaps gives a chromosome its peculiar identity, even a raison d'etre.
The particular set of genes on a chromosome give it its identity, but there (mostly) isn't anything special about which genes are where. Big chunks of genes can be swapped between chromosomes without it having any real effect on the organism, or example.