28566 has 24 divisors (see below), whose sum is σ = 66360. Its totient is φ = 9108.

The previous prime is 28559. The next prime is 28571. The reversal of 28566 is 66582.

28566 = 83² + 84² + ... + 86².

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1231 + ... + 1253.

It is an arithmetic number, because the mean of its divisors is an integer number (2765).

2²⁸⁵⁶⁶ is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28566, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33180).

28566 is an abundant number, since it is smaller than the sum of its proper divisors (37794).

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

28566 is a wasteful number, since it uses less digits than its factorization.

28566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57 (or 28 counting only the distinct ones).

The product of its digits is 2880, while the sum is 27.

The square root of 28566 is about 169.0147922520. The cubic root of 28566 is about 30.5691345828.

It can be divided in two parts, 285 and 66, that added together give a triangular number (351 = T₂₆).

The spelling of 28566 in words is "twenty-eight thousand, five hundred sixty-six".