280345 has 16 divisors (see below), whose sum is σ = 383040. Its totient is φ = 195264.

The previous prime is 280339. The next prime is 280351. The reversal of 280345 is 543082.

It is an interprime number because it is at equal distance from previous prime (280339) and next prime (280351).

It is a cyclic number.

It is not a de Polignac number, because 280345 - 2³ = 280337 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1122 + ... + 1348.

It is an arithmetic number, because the mean of its divisors is an integer number (23940).

2²⁸⁰³⁴⁵ is an apocalyptic number.

It is an amenable number.

280345 is a deficient number, since it is larger than the sum of its proper divisors (102695).

280345 is a wasteful number, since it uses less digits than its factorization.

280345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 264.

The product of its (nonzero) digits is 960, while the sum is 22.

The square root of 280345 is about 529.4761562148. The cubic root of 280345 is about 65.4481846489.

It can be divided in two parts, 280 and 345, that added together give a 4-th power (625 = 5⁴).

The spelling of 280345 in words is "two hundred eighty thousand, three hundred forty-five".