280705 has 8 divisors (see below), whose sum is σ = 347904. Its totient is φ = 217200.

The previous prime is 280703. The next prime is 280711. The reversal of 280705 is 507082.

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

It is not a de Polignac number, because 280705 - 2¹ = 280703 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (280703) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 751 + ... + 1060.

It is an arithmetic number, because the mean of its divisors is an integer number (43488).

2²⁸⁰⁷⁰⁵ is an apocalyptic number.

It is an amenable number.

280705 is a deficient number, since it is larger than the sum of its proper divisors (67199).

280705 is a wasteful number, since it uses less digits than its factorization.

280705 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1847.

The product of its (nonzero) digits is 560, while the sum is 22.

The square root of 280705 is about 529.8160057982. The cubic root of 280705 is about 65.4761873698.

Adding to 280705 its reverse (507082), we get a palindrome (787787).

The spelling of 280705 in words is "two hundred eighty thousand, seven hundred five".