Talk:Pernicious numbers

C solution too cryptic?

Hi, the C solution is a bit mysterious to me. The for loop seems to "remove the zeros" if I understand correctly, but then what's so special about 2693408940 ?? How can a simple bitwise & tell if the number of 1 (which is now the length since all zeros have been removed) is prime? A bit of explanation in the introduction of the section or in comment would be welcome--Grondilu (talk) 14:43, 12 March 2014 (UTC)