7816642561

Appears in sequences

• Composite integers n such that n-1 divided by the binary period of 1/n (=A007733(n)) equals an integral power of 2.at n=5A243050
• Carmichael numbers whose index is a power of 2 (see A174590).at n=0A306828
• Carmichael numbers k for which bigomega(phi(k)) < bigomega(k-1), where bigomega gives the number of prime divisors, counted with multiplicity.at n=19A339909