280661 has 8 divisors (see below), whose sum is σ = 294624. Its totient is φ = 267120.

The previous prime is 280639. The next prime is 280673. The reversal of 280661 is 166082.

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

It is a cyclic number.

It is not a de Polignac number, because 280661 - 2⁶ = 280597 is a prime.

It is a Duffinian number.

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 280661.

It is not an unprimeable number, because it can be changed into a prime (280681) 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 7 ways as a sum of consecutive naturals, for example, 2570 + ... + 2676.

It is an arithmetic number, because the mean of its divisors is an integer number (36828).

2²⁸⁰⁶⁶¹ is an apocalyptic number.

It is an amenable number.

280661 is a deficient number, since it is larger than the sum of its proper divisors (13963).

280661 is a wasteful number, since it uses less digits than its factorization.

280661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 211.

The product of its (nonzero) digits is 576, while the sum is 23.

The square root of 280661 is about 529.7744803216. The cubic root of 280661 is about 65.4727660998.

The spelling of 280661 in words is "two hundred eighty thousand, six hundred sixty-one".