666604617607 has 2 divisors, whose sum is σ = 666604617608. Its totient is φ = 666604617606.

The previous prime is 666604617599. The next prime is 666604617673. The reversal of 666604617607 is 706716406666.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666604617607 - 2³ = 666604617599 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666604618607) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333302308803 + 333302308804.

It is an arithmetic number, because the mean of its divisors is an integer number (333302308804).

Almost surely, 2^666604617607 is an apocalyptic number.

666604617607 is a deficient number, since it is larger than the sum of its proper divisors (1).

666604617607 is an equidigital number, since it uses as much as digits as its factorization.

666604617607 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 9144576, while the sum is 55.

The spelling of 666604617607 in words is "six hundred sixty-six billion, six hundred four million, six hundred seventeen thousand, six hundred seven".