
Jesse E. answered 07/11/19
Experienced Biochemistry Tutor
Interestingly enough, there was a research article in 1986 that discusses this same problem. Referring to “Extension of Rules A-1.1 and A-2.5 Concerning Numerical Terms Used in Organic Chemical Nomenclature”, Pure Appl. Chem., 1986, 58, 1693-1696 , a table exists with prefixes for molecules up to 9000. To name a compound, IUPAC names the unit first, then the tens, hundreds, and thousands place.
For your example of C205H412, it would be called pentadictane.