A little further testing shows me that these first two options I offered
don't improve your original formula but the third does (there must be values
stored as text). Also, VLOOKUP does not seem to accept the VALUE(your_range)
when I try to commit it as an array function, so you will have to use the
INDEX and MATCH combination (until someone else shows us differently)

=IF(ISNA(INDEX([Book1]Sheet1!$D$1:$D$17174,MATCH(A144,[Book1]Sheet1!$A$1:$A$17174,0))),INDEX([Book1]Sheet1!$D$1:$D$17174,MATCH(value(A144),value([Book1]Sheet1!$A$1:$A$17174),0)),INDEX([Book1]Sheet1!$D$1:$D$17174,MATCH(A144,[Book1]Sheet1!$A$1:$A$17174,0)))

which is an array formula so commit using Control+Shift+Enter