285861 has 4 divisors (see below), whose sum is σ = 381152. Its totient is φ = 190572.

The previous prime is 285841. The next prime is 285871. The reversal of 285861 is 168582.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 285861 - 2¹¹ = 283813 is a prime.

It is a super-2 number, since 2×285861² = 163433022642, which contains 22 as substring.

It is a D-number.

It is a Duffinian number.

It is a congruent number.

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 3 ways as a sum of consecutive naturals, for example, 47641 + ... + 47646.

It is an arithmetic number, because the mean of its divisors is an integer number (95288).

2²⁸⁵⁸⁶¹ is an apocalyptic number.

It is an amenable number.

285861 is a deficient number, since it is larger than the sum of its proper divisors (95291).

285861 is an equidigital number, since it uses as much as digits as its factorization.

285861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 95290.

The product of its digits is 3840, while the sum is 30.

The square root of 285861 is about 534.6597048591. The cubic root of 285861 is about 65.8746472862.

The spelling of 285861 in words is "two hundred eighty-five thousand, eight hundred sixty-one".