257685 has 16 divisors (see below), whose sum is σ = 423360. Its totient is φ = 133760.

The previous prime is 257671. The next prime is 257687. The reversal of 257685 is 586752.

257685 = T₂₂₂ + T₂₂₃ + ... + T₂₃₁.

257685 = 156² + 157² + ... + 165².

It is a happy number.

It is not a de Polignac number, because 257685 - 2¹⁰ = 256661 is a prime.

It is a Curzon number.

It is a plaindrome in base 11.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (257687) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 406 + ... + 824.

It is an arithmetic number, because the mean of its divisors is an integer number (26460).

2²⁵⁷⁶⁸⁵ is an apocalyptic number.

It is an amenable number.

257685 is a deficient number, since it is larger than the sum of its proper divisors (165675).

257685 is a wasteful number, since it uses less digits than its factorization.

257685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 468.

The product of its digits is 16800, while the sum is 33.

The square root of 257685 is about 507.6268314422. The cubic root of 257685 is about 63.6350485195.

The spelling of 257685 in words is "two hundred fifty-seven thousand, six hundred eighty-five".