280385 has 8 divisors (see below), whose sum is σ = 384576. Its totient is φ = 192240.

The previous prime is 280373. The next prime is 280409. The reversal of 280385 is 583082.

280385 = T₁₄ + T₁₅ + ... + T₁₁₈.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 280385 - 2⁶ = 280321 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 280385.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3971 + ... + 4040.

It is an arithmetic number, because the mean of its divisors is an integer number (48072).

2²⁸⁰³⁸⁵ is an apocalyptic number.

It is an amenable number.

280385 is a deficient number, since it is larger than the sum of its proper divisors (104191).

280385 is an equidigital number, since it uses as much as digits as its factorization.

280385 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8023.

The product of its (nonzero) digits is 1920, while the sum is 26.

The square root of 280385 is about 529.5139280510. The cubic root of 280385 is about 65.4512972457.

The spelling of 280385 in words is "two hundred eighty thousand, three hundred eighty-five".