257666065213 has 2 divisors, whose sum is σ = 257666065214. Its totient is φ = 257666065212.

The previous prime is 257666065187. The next prime is 257666065243. The reversal of 257666065213 is 312560666752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 161304247129 + 96361818084 = 401627^2 + 310422^2 .

It is a cyclic number.

It is not a de Polignac number, because 257666065213 - 2²⁵ = 257632510781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257666065243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128833032606 + 128833032607.

It is an arithmetic number, because the mean of its divisors is an integer number (128833032607).

Almost surely, 2^257666065213 is an apocalyptic number.

It is an amenable number.

257666065213 is a deficient number, since it is larger than the sum of its proper divisors (1).

257666065213 is an equidigital number, since it uses as much as digits as its factorization.

257666065213 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2721600, while the sum is 49.

The spelling of 257666065213 in words is "two hundred fifty-seven billion, six hundred sixty-six million, sixty-five thousand, two hundred thirteen".