28280 has 32 divisors (see below), whose sum is σ = 73440. Its totient is φ = 9600.

The previous prime is 28279. The next prime is 28283. The reversal of 28280 is 8282.

It is a Smith number, since the sum of its digits (20) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a plaindrome in base 12.

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 (28283) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 230 + ... + 330.

It is an arithmetic number, because the mean of its divisors is an integer number (2295).

2²⁸²⁸⁰ is an apocalyptic number.

28280 is a gapful number since it is divisible by the number (20) 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 28280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36720).

28280 is an abundant number, since it is smaller than the sum of its proper divisors (45160).

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

28280 is a wasteful number, since it uses less digits than its factorization.

28280 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 119 (or 115 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 20.

The square root of 28280 is about 168.1665840766. The cubic root of 28280 is about 30.4667738144.

The spelling of 28280 in words is "twenty-eight thousand, two hundred eighty".