666666631207 has 2 divisors, whose sum is σ = 666666631208. Its totient is φ = 666666631206.

The previous prime is 666666631201. The next prime is 666666631229. The reversal of 666666631207 is 702136666666.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 666666631207 - 2⁷ = 666666631079 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (666666631201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333333315603 + 333333315604.

It is an arithmetic number, because the mean of its divisors is an integer number (333333315604).

Almost surely, 2^666666631207 is an apocalyptic number.

666666631207 is a deficient number, since it is larger than the sum of its proper divisors (1).

666666631207 is an equidigital number, since it uses as much as digits as its factorization.

666666631207 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11757312, while the sum is 55.

The spelling of 666666631207 in words is "six hundred sixty-six billion, six hundred sixty-six million, six hundred thirty-one thousand, two hundred seven".