28707865 has 4 divisors (see below), whose sum is σ = 34449444. Its totient is φ = 22966288.

The previous prime is 28707863. The next prime is 28707869. The reversal of 28707865 is 56870782.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16232841 + 12475024 = 4029^2 + 3532^2 .

It is a cyclic number.

It is not a de Polignac number, because 28707865 - 2¹ = 28707863 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28707863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2870782 + ... + 2870791.

It is an arithmetic number, because the mean of its divisors is an integer number (8612361).

Almost surely, 2^28707865 is an apocalyptic number.

It is an amenable number.

28707865 is a deficient number, since it is larger than the sum of its proper divisors (5741579).

28707865 is an equidigital number, since it uses as much as digits as its factorization.

28707865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5741578.

The product of its (nonzero) digits is 188160, while the sum is 43.

The square root of 28707865 is about 5357.9720977250. The cubic root of 28707865 is about 306.1965537719.

The spelling of 28707865 in words is "twenty-eight million, seven hundred seven thousand, eight hundred sixty-five".