This number is a prime.
1 + 1/2 + 1/4 + ... + 1/(p-1) first exceeds 4 at the beast prime p = 266624669. [Merickel]
1 + 1/2 + 1/4 + ... + 1/(p-1) first exceeds 4 at the beast prime p = 266624669. [Merickel]