285805 has 8 divisors (see below), whose sum is σ = 369432. Its totient is φ = 211008.

The previous prime is 285781. The next prime is 285823. The reversal of 285805 is 508582.

It can be written as a sum of positive squares in 4 ways, for example, as 3844 + 281961 = 62^2 + 531^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 285805 - 2⁵ = 285773 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2134 + ... + 2263.

It is an arithmetic number, because the mean of its divisors is an integer number (46179).

2²⁸⁵⁸⁰⁵ is an apocalyptic number.

It is an amenable number.

285805 is a deficient number, since it is larger than the sum of its proper divisors (83627).

285805 is a wasteful number, since it uses less digits than its factorization.

285805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4415.

The product of its (nonzero) digits is 3200, while the sum is 28.

The square root of 285805 is about 534.6073325348. The cubic root of 285805 is about 65.8703454038.

The spelling of 285805 in words is "two hundred eighty-five thousand, eight hundred five".