28785 has 16 divisors (see below), whose sum is σ = 48960. Its totient is φ = 14400.

The previous prime is 28771. The next prime is 28789. The reversal of 28785 is 58782.

It is not a de Polignac number, because 28785 - 2⁵ = 28753 is a prime.

Its product of digits (4480) is a multiple of the sum of its prime divisors (128).

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 235 + ... + 335.

It is an arithmetic number, because the mean of its divisors is an integer number (3060).

2²⁸⁷⁸⁵ is an apocalyptic number.

It is an amenable number.

28785 is a deficient number, since it is larger than the sum of its proper divisors (20175).

28785 is a wasteful number, since it uses less digits than its factorization.

28785 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128.

The product of its digits is 4480, while the sum is 30.

The square root of 28785 is about 169.6614275550. The cubic root of 28785 is about 30.6470547783.

The spelling of 28785 in words is "twenty-eight thousand, seven hundred eighty-five".