280728 has 48 divisors (see below), whose sum is σ = 870480. Its totient is φ = 80064.

The previous prime is 280717. The next prime is 280729. The reversal of 280728 is 827082.

280728 is a Rhonda number in base 16.

It is a nialpdrome in base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (280729) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 226 + ... + 782.

It is an arithmetic number, because the mean of its divisors is an integer number (18135).

2²⁸⁰⁷²⁸ is an apocalyptic number.

280728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 280728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (435240).

280728 is an abundant number, since it is smaller than the sum of its proper divisors (589752).

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

280728 is a wasteful number, since it uses less digits than its factorization.

280728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 576 (or 569 counting only the distinct ones).

The product of its (nonzero) digits is 1792, while the sum is 27.

The square root of 280728 is about 529.8377110022. The cubic root of 280728 is about 65.4779756187.

The spelling of 280728 in words is "two hundred eighty thousand, seven hundred twenty-eight".