257329 has 4 divisors (see below), whose sum is σ = 272484. Its totient is φ = 242176.

The previous prime is 257321. The next prime is 257339. The reversal of 257329 is 923752.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 178929 + 78400 = 423^2 + 280^2 .

It is a cyclic number.

It is not a de Polignac number, because 257329 - 2³ = 257321 is a prime.

It is a Duffinian number.

257329 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 257297 and 257306.

It is not an unprimeable number, because it can be changed into a prime (257321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7552 + ... + 7585.

It is an arithmetic number, because the mean of its divisors is an integer number (68121).

2²⁵⁷³²⁹ is an apocalyptic number.

It is an amenable number.

257329 is a deficient number, since it is larger than the sum of its proper divisors (15155).

257329 is a wasteful number, since it uses less digits than its factorization.

257329 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15154.

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

The square root of 257329 is about 507.2760589659. The cubic root of 257329 is about 63.6057304015.

The spelling of 257329 in words is "two hundred fifty-seven thousand, three hundred twenty-nine".