280605 has 16 divisors (see below), whose sum is σ = 483840. Its totient is φ = 138048.

The previous prime is 280603. The next prime is 280607. The reversal of 280605 is 506082.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (280603) and next prime (280607).

It is not a de Polignac number, because 280605 - 2¹ = 280603 is a prime.

It is a d-powerful number, because it can be written as 2⁵ + 8³ + 6⁷ + 0 + 0 + 5³ .

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 280605.

It is not an unprimeable number, because it can be changed into a prime (280603) by changing a digit.

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 15 ways as a sum of consecutive naturals, for example, 525 + ... + 914.

It is an arithmetic number, because the mean of its divisors is an integer number (30240).

2²⁸⁰⁶⁰⁵ is an apocalyptic number.

It is an amenable number.

280605 is a deficient number, since it is larger than the sum of its proper divisors (203235).

280605 is a wasteful number, since it uses less digits than its factorization.

280605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1460.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 280605 is about 529.7216250069. The cubic root of 280605 is about 65.4684112390.

Adding to 280605 its reverse (506082), we get a palindrome (786687).

The spelling of 280605 in words is "two hundred eighty thousand, six hundred five".