280428 has 12 divisors (see below), whose sum is σ = 654360. Its totient is φ = 93472.

The previous prime is 280411. The next prime is 280451. The reversal of 280428 is 824082.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 280398 and 280407.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 280428.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11673 + ... + 11696.

It is an arithmetic number, because the mean of its divisors is an integer number (54530).

2²⁸⁰⁴²⁸ is an apocalyptic number.

It is an amenable number.

280428 is an abundant number, since it is smaller than the sum of its proper divisors (373932).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

280428 is a wasteful number, since it uses less digits than its factorization.

280428 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23376 (or 23374 counting only the distinct ones).

The product of its (nonzero) digits is 1024, while the sum is 24.

The square root of 280428 is about 529.5545297701. The cubic root of 280428 is about 65.4546429572.

The spelling of 280428 in words is "two hundred eighty thousand, four hundred twenty-eight".