285831 has 24 divisors (see below), whose sum is σ = 509600. Its totient is φ = 150336.

The previous prime is 285827. The next prime is 285839. The reversal of 285831 is 138582.

It is a happy number.

It is not a de Polignac number, because 285831 - 2² = 285827 is a prime.

It is a super-2 number, since 2×285831² = 163398721122, which contains 22 as substring.

It is a d-powerful number, because it can be written as 2¹⁴ + 8⁴ + 8⁶ + 5⁵ + 3⁴ + 1 .

It is a junction number, because it is equal to n+sod(n) for n = 285795 and 285804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285839) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 645 + ... + 993.

2²⁸⁵⁸³¹ is an apocalyptic number.

285831 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

285831 is a deficient number, since it is larger than the sum of its proper divisors (223769).

285831 is a wasteful number, since it uses less digits than its factorization.

285831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 375 (or 372 counting only the distinct ones).

The product of its digits is 1920, while the sum is 27.

The square root of 285831 is about 534.6316488948. The cubic root of 285831 is about 65.8723427762.

The spelling of 285831 in words is "two hundred eighty-five thousand, eight hundred thirty-one".