257826907649 has 2 divisors, whose sum is σ = 257826907650. Its totient is φ = 257826907648.

The previous prime is 257826907573. The next prime is 257826907699. The reversal of 257826907649 is 946709628752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 192703440400 + 65123467249 = 438980^2 + 255193^2 .

It is a cyclic number.

It is not a de Polignac number, because 257826907649 - 2²⁴ = 257810130433 is a prime.

It is not a weakly prime, because it can be changed into another prime (257826907699) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128913453824 + 128913453825.

It is an arithmetic number, because the mean of its divisors is an integer number (128913453825).

Almost surely, 2^257826907649 is an apocalyptic number.

It is an amenable number.

257826907649 is a deficient number, since it is larger than the sum of its proper divisors (1).

257826907649 is an equidigital number, since it uses as much as digits as its factorization.

257826907649 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 91445760, while the sum is 65.

The spelling of 257826907649 in words is "two hundred fifty-seven billion, eight hundred twenty-six million, nine hundred seven thousand, six hundred forty-nine".