Here's another one. You'll notice that typically there's slightly more numbers that factor into a product of an odd number of primes (i.e. 2,3,5,7,8,11,12,13,...) than into an even number of primes (4,6,9,10,14,15,...). If this is the case then RH is true. You can make this into a more precise question about the partial sums of the Liouville function and make it an equivalence.