How about none of the above? It looks like that number was printed using a rubber stamp, maybe of the kind that had bands of numbers which were indexed to create the sequence. The horizontal line at the bottom of those two characters that look like 2's or Z's could be an artifact from the stamp, and they are in fact 7's... so maybe 2-78642 or even 2-78647? Zooming it in really big on my screen I'd lean toward 2-78642. The shape of the last character looks similar to the leading 2.