666604617673 has 2 divisors, whose sum is σ = 666604617674. Its totient is φ = 666604617672.

The previous prime is 666604617607. The next prime is 666604617727. The reversal of 666604617673 is 376716406666.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 345129225529 + 321475392144 = 587477^2 + 566988^2 .

It is a cyclic number.

It is not a de Polignac number, because 666604617673 - 2²⁹ = 666067746761 is a prime.

It is not a weakly prime, because it can be changed into another prime (666604614673) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333302308836 + 333302308837.

It is an arithmetic number, because the mean of its divisors is an integer number (333302308837).

Almost surely, 2^666604617673 is an apocalyptic number.

It is an amenable number.

666604617673 is a deficient number, since it is larger than the sum of its proper divisors (1).

666604617673 is an equidigital number, since it uses as much as digits as its factorization.

666604617673 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 27433728, while the sum is 58.

The spelling of 666604617673 in words is "six hundred sixty-six billion, six hundred four million, six hundred seventeen thousand, six hundred seventy-three".