280045 has 4 divisors (see below), whose sum is σ = 336060. Its totient is φ = 224032.

The previous prime is 280037. The next prime is 280061. The reversal of 280045 is 540082.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 195364 + 84681 = 442^2 + 291^2 .

It is a cyclic number.

It is not a de Polignac number, because 280045 - 2³ = 280037 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 28000 + ... + 28009.

It is an arithmetic number, because the mean of its divisors is an integer number (84015).

2²⁸⁰⁰⁴⁵ is an apocalyptic number.

It is an amenable number.

280045 is a deficient number, since it is larger than the sum of its proper divisors (56015).

280045 is an equidigital number, since it uses as much as digits as its factorization.

280045 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 56014.

The product of its (nonzero) digits is 320, while the sum is 19.

The square root of 280045 is about 529.1927815078. The cubic root of 280045 is about 65.4248307299.

The spelling of 280045 in words is "two hundred eighty thousand, forty-five".