28320765 has 16 divisors (see below), whose sum is σ = 49432896. Its totient is φ = 13731200.

The previous prime is 28320749. The next prime is 28320769. The reversal of 28320765 is 56702382.

It is not a de Polignac number, because 28320765 - 2⁴ = 28320749 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33).

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28320769) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85656 + ... + 85985.

It is an arithmetic number, because the mean of its divisors is an integer number (3089556).

Almost surely, 2^28320765 is an apocalyptic number.

It is an amenable number.

28320765 is a deficient number, since it is larger than the sum of its proper divisors (21112131).

28320765 is a wasteful number, since it uses less digits than its factorization.

28320765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171660.

The product of its (nonzero) digits is 20160, while the sum is 33.

The square root of 28320765 is about 5321.7257539261. The cubic root of 28320765 is about 304.8140584825.

The spelling of 28320765 in words is "twenty-eight million, three hundred twenty thousand, seven hundred sixty-five".