Is pyrene an aromatic hydrocarbon?

Yes, pyrene is an aromatic hydrocarbon.
See .
Pyrene belongs to the group of called polycyclic aromatic compounds.
The structure of pyrene is
The above structure shows three benzene rings.
We can draw another structure in which the fourth ring is also a benzene ring.
So pyrene is a resonance hybrid with four aromatic rings.
Also, the carbon atoms around the perimeter have 14 ##p## orbital electrons. This satisfies the Hückel 4##n## +2 rule for aromaticity (##n## = 3).