28864 has 28 divisors (see below), whose sum is σ = 64008. Its totient is φ = 12800.

The previous prime is 28859. The next prime is 28867. The reversal of 28864 is 46882.

28864 = 12² + 13² + ... + 44².

Its product of digits (3072) is a multiple of the sum of its prime factors (64).

It is a nialpdrome in base 15.

It is a zygodrome in base 2 and base 15.

It is not an unprimeable number, because it can be changed into a prime (28867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 684 + ... + 724.

It is an arithmetic number, because the mean of its divisors is an integer number (2286).

2²⁸⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32004).

28864 is an abundant number, since it is smaller than the sum of its proper divisors (35144).

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

28864 is a wasteful number, since it uses less digits than its factorization.

28864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 64 (or 54 counting only the distinct ones).

The product of its digits is 3072, while the sum is 28.

The square root of 28864 is about 169.8940846528. The cubic root of 28864 is about 30.6750659623.

The spelling of 28864 in words is "twenty-eight thousand, eight hundred sixty-four".