257387 has 6 divisors (see below), whose sum is σ = 278892. Its totient is φ = 237432.

The previous prime is 257381. The next prime is 257399. The reversal of 257387 is 783752.

It is not a de Polignac number, because 257387 - 2⁴ = 257371 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 8.

It is not an unprimeable number, because it can be changed into a prime (257381) 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 5 ways as a sum of consecutive naturals, for example, 593 + ... + 930.

It is an arithmetic number, because the mean of its divisors is an integer number (46482).

2²⁵⁷³⁸⁷ is an apocalyptic number.

257387 is a deficient number, since it is larger than the sum of its proper divisors (21505).

257387 is a wasteful number, since it uses less digits than its factorization.

257387 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1549 (or 1536 counting only the distinct ones).

The product of its digits is 11760, while the sum is 32.

The square root of 257387 is about 507.3332238283. Note that the first 3 decimals coincide. The cubic root of 257387 is about 63.6105087918.

The spelling of 257387 in words is "two hundred fifty-seven thousand, three hundred eighty-seven".