280636 has 12 divisors (see below), whose sum is σ = 520128. Its totient is φ = 132032.

The previous prime is 280627. The next prime is 280639. The reversal of 280636 is 636082.

It is a self number, because there is not a number n which added to its sum of digits gives 280636.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280639) by changing a digit.

280636 is an untouchable number, because it is not equal to the sum of proper divisors of any 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 3 ways as a sum of consecutive naturals, for example, 1996 + ... + 2131.

It is an arithmetic number, because the mean of its divisors is an integer number (43344).

2²⁸⁰⁶³⁶ is an apocalyptic number.

It is an amenable number.

280636 is a deficient number, since it is larger than the sum of its proper divisors (239492).

280636 is a wasteful number, since it uses less digits than its factorization.

280636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4148 (or 4146 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 25.

The square root of 280636 is about 529.7508848506. The cubic root of 280636 is about 65.4708220371.

The spelling of 280636 in words is "two hundred eighty thousand, six hundred thirty-six".