280390 has 16 divisors (see below), whose sum is σ = 550800. Its totient is φ = 101920.

The previous prime is 280373. The next prime is 280409. The reversal of 280390 is 93082.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is an unprimeable number.

280390 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, 1165 + ... + 1384.

It is an arithmetic number, because the mean of its divisors is an integer number (34425).

2²⁸⁰³⁹⁰ is an apocalyptic number.

280390 is a deficient number, since it is larger than the sum of its proper divisors (270410).

280390 is a wasteful number, since it uses less digits than its factorization.

280390 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2567.

The product of its (nonzero) digits is 432, while the sum is 22.

The square root of 280390 is about 529.5186493411. The cubic root of 280390 is about 65.4516862995.

The spelling of 280390 in words is "two hundred eighty thousand, three hundred ninety".