257686047569 has 2 divisors, whose sum is σ = 257686047570. Its totient is φ = 257686047568.

The previous prime is 257686047559. The next prime is 257686047587. The reversal of 257686047569 is 965740686752.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 167229469969 + 90456577600 = 408937^2 + 300760^2 .

It is a cyclic number.

It is not a de Polignac number, because 257686047569 - 2⁸ = 257686047313 is a prime.

It is a super-2 number, since 2×257686047569² (a number of 24 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (257686047559) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128843023784 + 128843023785.

It is an arithmetic number, because the mean of its divisors is an integer number (128843023785).

Almost surely, 2^257686047569 is an apocalyptic number.

It is an amenable number.

257686047569 is a deficient number, since it is larger than the sum of its proper divisors (1).

257686047569 is an equidigital number, since it uses as much as digits as its factorization.

257686047569 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 152409600, while the sum is 65.

The spelling of 257686047569 in words is "two hundred fifty-seven billion, six hundred eighty-six million, forty-seven thousand, five hundred sixty-nine".