257931 has 16 divisors (see below), whose sum is σ = 393120. Its totient is φ = 167040.

The previous prime is 257921. The next prime is 257947. The reversal of 257931 is 139752.

It is not a de Polignac number, because 257931 - 2⁶ = 257867 is a prime.

It is a super-2 number, since 2×257931² = 133056801522, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a zygodrome in base 3.

It is a junction number, because it is equal to n+sod(n) for n = 257895 and 257904.

It is not an unprimeable number, because it can be changed into a prime (257921) 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 in 15 ways as a sum of consecutive naturals, for example, 991 + ... + 1223.

It is an arithmetic number, because the mean of its divisors is an integer number (24570).

2²⁵⁷⁹³¹ is an apocalyptic number.

257931 is a deficient number, since it is larger than the sum of its proper divisors (135189).

257931 is a wasteful number, since it uses less digits than its factorization.

257931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 283 (or 277 counting only the distinct ones).

The product of its digits is 1890, while the sum is 27.

The square root of 257931 is about 507.8690776175. The cubic root of 257931 is about 63.6552918956.

The spelling of 257931 in words is "two hundred fifty-seven thousand, nine hundred thirty-one".