285891 has 8 divisors (see below), whose sum is σ = 383760. Its totient is φ = 189312.

The previous prime is 285871. The next prime is 285937. The reversal of 285891 is 198582.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 285891 - 2⁶ = 285827 is a prime.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 285891.

It is not an unprimeable number, because it can be changed into a prime (285841) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 495 + ... + 903.

It is an arithmetic number, because the mean of its divisors is an integer number (47970).

2²⁸⁵⁸⁹¹ is an apocalyptic number.

285891 is a deficient number, since it is larger than the sum of its proper divisors (97869).

285891 is a wasteful number, since it uses less digits than its factorization.

285891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 645.

The product of its digits is 5760, while the sum is 33.

The square root of 285891 is about 534.6877593512. The cubic root of 285891 is about 65.8769516349.

It can be divided in two parts, 285 and 891, that added together give a triangular number (1176 = T₄₈).

The spelling of 285891 in words is "two hundred eighty-five thousand, eight hundred ninety-one".