28864239 has 4 divisors (see below), whose sum is σ = 38485656. Its totient is φ = 19242824.

The previous prime is 28864237. The next prime is 28864259. The reversal of 28864239 is 93246882.

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

It is a cyclic number.

It is not a de Polignac number, because 28864239 - 2¹ = 28864237 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 28864239.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28864237) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4810704 + ... + 4810709.

It is an arithmetic number, because the mean of its divisors is an integer number (9621414).

Almost surely, 2^28864239 is an apocalyptic number.

28864239 is a deficient number, since it is larger than the sum of its proper divisors (9621417).

28864239 is an equidigital number, since it uses as much as digits as its factorization.

28864239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9621416.

The product of its digits is 165888, while the sum is 42.

The square root of 28864239 is about 5372.5449276856. The cubic root of 28864239 is about 306.7515062738.

The spelling of 28864239 in words is "twenty-eight million, eight hundred sixty-four thousand, two hundred thirty-nine".