28764 has 36 divisors (see below), whose sum is σ = 78624. Its totient is φ = 8832.

The previous prime is 28759. The next prime is 28771. The reversal of 28764 is 46782.

28764 = T₃₂ + T₃₃ + ... + T₅₈.

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 28764.

It is an unprimeable number.

28764 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

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 11 ways as a sum of consecutive naturals, for example, 589 + ... + 635.

It is an arithmetic number, because the mean of its divisors is an integer number (2184).

28764 is a Friedman number, since it can be written as (7^4*2-8)*6, using all its digits and the basic arithmetic operations.

2²⁸⁷⁶⁴ 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 28764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39312).

28764 is an abundant number, since it is smaller than the sum of its proper divisors (49860).

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

28764 is a wasteful number, since it uses less digits than its factorization.

28764 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74 (or 69 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 28764 is about 169.5995283012. The cubic root of 28764 is about 30.6396001466.

It can be divided in two parts, 287 and 64, that added together give a triangular number (351 = T₂₆).

The spelling of 28764 in words is "twenty-eight thousand, seven hundred sixty-four".