285880 has 32 divisors (see below), whose sum is σ = 735840. Its totient is φ = 97920.

The previous prime is 285871. The next prime is 285937. The reversal of 285880 is 88582.

285880 = T₉₉ + T₁₀₀ + ... + T₁₃₈.

It is a congruent number.

It is an unprimeable number.

285880 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, 231 + ... + 790.

It is an arithmetic number, because the mean of its divisors is an integer number (22995).

2²⁸⁵⁸⁸⁰ is an apocalyptic number.

285880 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

285880 is an abundant number, since it is smaller than the sum of its proper divisors (449960).

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

285880 is a wasteful number, since it uses less digits than its factorization.

285880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1039 (or 1035 counting only the distinct ones).

The product of its (nonzero) digits is 5120, while the sum is 31.

The square root of 285880 is about 534.6774728750. The cubic root of 285880 is about 65.8761067258.

The spelling of 285880 in words is "two hundred eighty-five thousand, eight hundred eighty".