No person or agency keeps track of the number of coins in circulation. In recent decades on average several billion have been minted annually so it would be utterly impossible to track them.
Formula is a word derived from Latin, so the correct formal plural for the word formula is formulae. However, because the word is often used by English speakers who have no background whit Latin, the plural of formulas has become more acceptable in recent decades.
There are two and one syllables in "recent" and "where," respectively.
In recent past
Yes, the word 'recently' is an adverb because it alters the meaning of a verb. An example would be 'he recently had the flu and was unable to go to school' where had/have is the verb.