257239 has 2 divisors, whose sum is σ = 257240. Its totient is φ = 257238.

The previous prime is 257221. The next prime is 257249. The reversal of 257239 is 932752.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 257239 - 2¹¹ = 255191 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (257219) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 128619 + 128620.

It is an arithmetic number, because the mean of its divisors is an integer number (128620).

2²⁵⁷²³⁹ is an apocalyptic number.

257239 is a deficient number, since it is larger than the sum of its proper divisors (1).

257239 is an equidigital number, since it uses as much as digits as its factorization.

257239 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3780, while the sum is 28.

The square root of 257239 is about 507.1873421133. The cubic root of 257239 is about 63.5983142361.

It can be divided in two parts, 257 and 239, that added together give a triangular number (496 = T₃₁).

The spelling of 257239 in words is "two hundred fifty-seven thousand, two hundred thirty-nine".