numdiv() does not take advantage of addprimes()

[Max Alekseyev <maxale@gmail.com>]

numdiv() somehow does not take advantage of addprimes() - see example below.
Is that intended?
Max

? addprimes([505471005740691524853293621])
%1 = [505471005740691524853293621]
? factor(fibonacci(277))
%2 =
[505471005740691524853293621 1]

[6861121308187330908986328104917 1]

? ##
  ***   last result computed in 0 ms.
? numdiv(fibonacci(277))
%3 = 4
? ##
  ***   last result computed in 12,210 ms.