As I know, there are two naming ways for SNP, one is on the basis of position of SNP on gene, for example +1123C>G and the other is rs2488457. In second naming system what is the meaning of number (2488457)?
the number (#) in the rs# does not have any especial meaning regarding that SNP and it is just a kind of accession number which is assigned for that SNP. you can search the rs# in the SNP database of NCBI (http://www.ncbi.nlm.nih.gov/snp/) and you will find a page containing useful data about that SNP.