fedcb59726a1348

irb(main):002:0> "fedcb59726a1348".to_i(16).pmbgood(16)
=> true
irb(main):003:0> "fedcb59726a1348".length
=> 15
irb(main):004:0> "fedcb59726a1348".to_i(16).pmbbad(16)
=> nil
irb(main):005:0> "fedcb59726a1348".to_i(16)
=> 1147797065081426760