66546555571 has 2 divisors, whose sum is σ = 66546555572. Its totient is φ = 66546555570.

The previous prime is 66546555553. The next prime is 66546555587. The reversal of 66546555571 is 17555564566.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 66546555571 - 2⁹ = 66546555059 is a prime.

It is a super-4 number, since 4×66546555571⁴ (a number of 44 digits) contains 4444 as substring. Note that it is a super-d number also for d = 2.

It is not a weakly prime, because it can be changed into another prime (66546555371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33273277785 + 33273277786.

It is an arithmetic number, because the mean of its divisors is an integer number (33273277786).

Almost surely, 2^66546555571 is an apocalyptic number.

66546555571 is a deficient number, since it is larger than the sum of its proper divisors (1).

66546555571 is an equidigital number, since it uses as much as digits as its factorization.

66546555571 is an evil number, because the sum of its binary digits is even.

The product of its digits is 18900000, while the sum is 55.

The spelling of 66546555571 in words is "sixty-six billion, five hundred forty-six million, five hundred fifty-five thousand, five hundred seventy-one".