666666631097 has 2 divisors, whose sum is σ = 666666631098. Its totient is φ = 666666631096.

The previous prime is 666666631091. The next prime is 666666631177. The reversal of 666666631097 is 790136666666.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 640857887296 + 25808743801 = 800536^2 + 160651^2 .

It is a cyclic number.

It is not a de Polignac number, because 666666631097 - 2⁸ = 666666630841 is a prime.

It is not a weakly prime, because it can be changed into another prime (666666631091) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 333333315548 + 333333315549.

It is an arithmetic number, because the mean of its divisors is an integer number (333333315549).

Almost surely, 2^666666631097 is an apocalyptic number.

It is an amenable number.

666666631097 is a deficient number, since it is larger than the sum of its proper divisors (1).

666666631097 is an equidigital number, since it uses as much as digits as its factorization.

666666631097 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 52907904, while the sum is 62.

The spelling of 666666631097 in words is "six hundred sixty-six billion, six hundred sixty-six million, six hundred thirty-one thousand, ninety-seven".