[silisili]

Not trying to be a jerk, but why is that interesting? Am I missing something more than all odd numbers end in 1, and primes by their nature cannot be even(except 2, as you mentioned).

[lkirkwood]

Just nitpick but all odd numbers end in an odd number, not 1, and all even numbers end in an even number i.e. a multiple of 2.

[silisili]

Sure, but OP was talking about binary representation.

[dmichulke]

GP's statement is true for all number systems with an even base (so also for binary and decimal)

[Etheryte]

All odd numbers end in 1 in binary.