285986 has 4 divisors (see below), whose sum is σ = 428982. Its totient is φ = 142992.

The previous prime is 285983. The next prime is 285997. The reversal of 285986 is 689582.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 689582 = 2 ⋅344791.

It can be written as a sum of positive squares in only one way, i.e., 207025 + 78961 = 455^2 + 281^2 .

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (285983) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 71495 + ... + 71498.

2²⁸⁵⁹⁸⁶ is an apocalyptic number.

285986 is a deficient number, since it is larger than the sum of its proper divisors (142996).

285986 is a wasteful number, since it uses less digits than its factorization.

285986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 142995.

The product of its digits is 34560, while the sum is 38.

The square root of 285986 is about 534.7765888668. The cubic root of 285986 is about 65.8842476759.

The spelling of 285986 in words is "two hundred eighty-five thousand, nine hundred eighty-six".