285280 has 24 divisors (see below), whose sum is σ = 674352. Its totient is φ = 114048.

The previous prime is 285251. The next prime is 285281. The reversal of 285280 is 82582.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (285281) by changing a digit.

285280 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 3 ways as a sum of consecutive naturals, for example, 732 + ... + 1051.

It is an arithmetic number, because the mean of its divisors is an integer number (28098).

2²⁸⁵²⁸⁰ is an apocalyptic number.

285280 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

285280 is an abundant number, since it is smaller than the sum of its proper divisors (389072).

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

285280 is a wasteful number, since it uses less digits than its factorization.

285280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1798 (or 1790 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 25.

The square root of 285280 is about 534.1160922496. The cubic root of 285280 is about 65.8299879017.

It can be divided in two parts, 285 and 280, that multiplied together give a triangular number (79800 = T₃₉₉).

The spelling of 285280 in words is "two hundred eighty-five thousand, two hundred eighty".