Alphanumeric preference between hexyl and heptyl
According to the IUPAC nomenclature, preference for placing prefixes is given in accordance with alphabetical order (just like in a standard English dictionary). It has nothing to do with the number of letters in a prefix. Since &quot;P&quot; in heptyl comes before &quot;X&quot; in hexyl, heptyl will be placed before hexyl in IUPAC nomenclature.
Hence, the correct name will be the one where heptyl is placed before hexyl (8-heptyl-10-hexylheptadecane).