257605 has 4 divisors (see below), whose sum is σ = 309132. Its totient is φ = 206080.

The previous prime is 257591. The next prime is 257611. The reversal of 257605 is 506752.

It is a happy number.

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 26244 + 231361 = 162^2 + 481^2 .

It is not a de Polignac number, because 257605 - 2⁹ = 257093 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 257605.

It is a congruent number.

It is an unprimeable number.

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, 25756 + ... + 25765.

It is an arithmetic number, because the mean of its divisors is an integer number (77283).

2²⁵⁷⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

257605 is a deficient number, since it is larger than the sum of its proper divisors (51527).

257605 is an equidigital number, since it uses as much as digits as its factorization.

257605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 51526.

The product of its (nonzero) digits is 2100, while the sum is 25.

The square root of 257605 is about 507.5480272841. The cubic root of 257605 is about 63.6284625317.

The spelling of 257605 in words is "two hundred fifty-seven thousand, six hundred five".