28547665 has 4 divisors (see below), whose sum is σ = 34257204. Its totient is φ = 22838128.

The previous prime is 28547639. The next prime is 28547689. The reversal of 28547665 is 56674582.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56674582 = 2 ⋅28337291.

It can be written as a sum of positive squares in 2 ways, for example, as 10297681 + 18249984 = 3209^2 + 4272^2 .

It is a cyclic number.

It is not a de Polignac number, because 28547665 - 2⁷ = 28547537 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2854762 + ... + 2854771.

It is an arithmetic number, because the mean of its divisors is an integer number (8564301).

Almost surely, 2^28547665 is an apocalyptic number.

It is an amenable number.

28547665 is a deficient number, since it is larger than the sum of its proper divisors (5709539).

28547665 is an equidigital number, since it uses as much as digits as its factorization.

28547665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5709538.

The product of its digits is 403200, while the sum is 43.

The square root of 28547665 is about 5343.0014972860. The cubic root of 28547665 is about 305.6259294778.

The spelling of 28547665 in words is "twenty-eight million, five hundred forty-seven thousand, six hundred sixty-five".