255891 has 4 divisors (see below), whose sum is σ = 341192. Its totient is φ = 170592.

The previous prime is 255887. The next prime is 255907. The reversal of 255891 is 198552.

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

It is not a de Polignac number, because 255891 - 2² = 255887 is a prime.

It is a D-number.

It is a Duffinian number.

255891 is a lucky number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 255891.

It is not an unprimeable number, because it can be changed into a prime (255841) 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, 42646 + ... + 42651.

It is an arithmetic number, because the mean of its divisors is an integer number (85298).

2²⁵⁵⁸⁹¹ is an apocalyptic number.

255891 is a deficient number, since it is larger than the sum of its proper divisors (85301).

255891 is an equidigital number, since it uses as much as digits as its factorization.

255891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 85300.

The product of its digits is 3600, while the sum is 30.

The square root of 255891 is about 505.8566990759. The cubic root of 255891 is about 63.4870289914.

The spelling of 255891 in words is "two hundred fifty-five thousand, eight hundred ninety-one".