Postal addressing standards in Chile

I need to ship a package to Chile, and I’m confused about what the various parts of the address represent.

After the street address, the person lists:

Rancagua, Del Libertador 84
Chile

On the line below Chile is a number that begins 072- and is folllowed by six digits, no spaces.

From what I can figure, Del Libertador is the “region,” not the province, which would be Cachapoal. I don’t have any idea what the number 84 represents. But would I list Del Libertador or Cachapoal in the province/state field on the USPS web site for purchasing postage?

The number below Chile does not match the format for Chilean postal codes. Is it a phone number???

Any help would be appreciated.