285220 has 24 divisors (see below), whose sum is σ = 645624. Its totient is φ = 105216.

The previous prime is 285199. The next prime is 285221. The reversal of 285220 is 22582.

It can be written as a sum of positive squares in 4 ways, for example, as 64 + 285156 = 8^2 + 534^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 289 + ... + 808.

It is an arithmetic number, because the mean of its divisors is an integer number (26901).

2²⁸⁵²²⁰ is an apocalyptic number.

285220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

285220 is an abundant number, since it is smaller than the sum of its proper divisors (360404).

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

285220 is a wasteful number, since it uses less digits than its factorization.

285220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1119 (or 1117 counting only the distinct ones).

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 285220 is about 534.0599217316. The cubic root of 285220 is about 65.8253724640.

It can be divided in two parts, 285 and 220, that added together give a palindrome (505).

The spelling of 285220 in words is "two hundred eighty-five thousand, two hundred twenty".