256287 has 4 divisors (see below), whose sum is σ = 341720. Its totient is φ = 170856.

The previous prime is 256279. The next prime is 256301. The reversal of 256287 is 782652.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 256287 - 2³ = 256279 is a prime.

It is an Ulam number.

It is a D-number.

It is a Duffinian number.

256287 is a lucky number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 256287.

It is not an unprimeable number, because it can be changed into a prime (256187) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42712 + ... + 42717.

It is an arithmetic number, because the mean of its divisors is an integer number (85430).

2²⁵⁶²⁸⁷ is an apocalyptic number.

256287 is a deficient number, since it is larger than the sum of its proper divisors (85433).

256287 is an equidigital number, since it uses as much as digits as its factorization.

256287 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85432.

The product of its digits is 6720, while the sum is 30.

The square root of 256287 is about 506.2479629589. The cubic root of 256287 is about 63.5197615557.

The spelling of 256287 in words is "two hundred fifty-six thousand, two hundred eighty-seven".