257291 has 4 divisors (see below), whose sum is σ = 258312. Its totient is φ = 256272.

The previous prime is 257287. The next prime is 257293. The reversal of 257291 is 192752.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 257291 - 2² = 257287 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 257291.

It is not an unprimeable number, because it can be changed into a prime (257293) 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, 176 + ... + 738.

It is an arithmetic number, because the mean of its divisors is an integer number (64578).

2²⁵⁷²⁹¹ is an apocalyptic number.

257291 is a deficient number, since it is larger than the sum of its proper divisors (1021).

257291 is an equidigital number, since it uses as much as digits as its factorization.

257291 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1020.

The product of its digits is 1260, while the sum is 26.

The square root of 257291 is about 507.2386026319. The cubic root of 257291 is about 63.6025993426.

The spelling of 257291 in words is "two hundred fifty-seven thousand, two hundred ninety-one".