285990 has 16 divisors (see below), whose sum is σ = 686448. Its totient is φ = 76256.

The previous prime is 285983. The next prime is 285997. The reversal of 285990 is 99582.

It is an interprime number because it is at equal distance from previous prime (285983) and next prime (285997).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285997) by changing a digit.

285990 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4737 + ... + 4796.

It is an arithmetic number, because the mean of its divisors is an integer number (42903).

2²⁸⁵⁹⁹⁰ is an apocalyptic number.

285990 is an abundant number, since it is smaller than the sum of its proper divisors (400458).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

285990 is a wasteful number, since it uses less digits than its factorization.

285990 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9543.

The product of its (nonzero) digits is 6480, while the sum is 33.

The square root of 285990 is about 534.7803287332. The cubic root of 285990 is about 65.8845548421.

It can be divided in two parts, 285 and 990, that added together give a triangular number (1275 = T₅₀).

The spelling of 285990 in words is "two hundred eighty-five thousand, nine hundred ninety".