As long as, as short as, as many as, and the like can be used in front of a number to emphasize how big or small the number is.
Here's what Practical English Usage says about this construction:
Before a number, as long as can be used to suggest great length.
These meetings can last as long as four hours.
As much/many as can be used before a number to mean 'the large amount/quantity of.
Some of these fish can weigh as much as 80kg.
There are sometimes as many as 40 students in the classes.
As little/few can be used to mean 'the small amount/quantity of'.
You can fly to Paris for as little as 20 euros.
Examples from the Corpus of Contemporary American English:
Our mission could've been as short as two and a half months, but it was extended to almost six months.
You may have to wait for as long as six months, and availability is severely limited.
Every year, as many as 60,000 come to the Mackinac Bridge for the Annual Bridge Walk.
As close as, as near as, as far as, and as far away as can be used before countries, cities, towns, etc. to emphasize the distance between the current location and the one being referred to.
Nuts on Clark imports products from as far as Australia and Brazil.
We received more than 2,000 entries from as near as Newark and as far away as Japan and Africa.
Dads came from as close as Pittsburgh and as far away as Wisconsin and Tennessee.