257399689 has 2 divisors, whose sum is σ = 257399690. Its totient is φ = 257399688.

The previous prime is 257399671. The next prime is 257399699. The reversal of 257399689 is 986993752.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 138415225 + 118984464 = 11765^2 + 10908^2 .

It is a cyclic number.

It is not a de Polignac number, because 257399689 - 2⁷ = 257399561 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (257399699) 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, 128699844 + 128699845.

It is an arithmetic number, because the mean of its divisors is an integer number (128699845).

Almost surely, 2^257399689 is an apocalyptic number.

It is an amenable number.

257399689 is a deficient number, since it is larger than the sum of its proper divisors (1).

257399689 is an equidigital number, since it uses as much as digits as its factorization.

257399689 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 7348320, while the sum is 58.

The square root of 257399689 is about 16043.6806562584. The cubic root of 257399689 is about 636.1155409260.

The spelling of 257399689 in words is "two hundred fifty-seven million, three hundred ninety-nine thousand, six hundred eighty-nine".