280855 has 4 divisors (see below), whose sum is σ = 337032. Its totient is φ = 224680.

The previous prime is 280843. The next prime is 280859. The reversal of 280855 is 558082.

280855 = 235² + 236² + ... + 239².

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 280855 - 2¹¹ = 278807 is a prime.

It is a Duffinian number.

280855 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280859) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28081 + ... + 28090.

It is an arithmetic number, because the mean of its divisors is an integer number (84258).

2²⁸⁰⁸⁵⁵ is an apocalyptic number.

280855 is a deficient number, since it is larger than the sum of its proper divisors (56177).

280855 is an equidigital number, since it uses as much as digits as its factorization.

280855 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56176.

The product of its (nonzero) digits is 3200, while the sum is 28.

The square root of 280855 is about 529.9575454694. The cubic root of 280855 is about 65.4878481040.

The spelling of 280855 in words is "two hundred eighty thousand, eight hundred fifty-five".