28288839 has 4 divisors (see below), whose sum is σ = 37718456. Its totient is φ = 18859224.

The previous prime is 28288829. The next prime is 28288859. The reversal of 28288839 is 93888282.

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

It is not a de Polignac number, because 28288839 - 2⁴ = 28288823 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28288829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4714804 + ... + 4714809.

It is an arithmetic number, because the mean of its divisors is an integer number (9429614).

Almost surely, 2^28288839 is an apocalyptic number.

28288839 is a deficient number, since it is larger than the sum of its proper divisors (9429617).

28288839 is an equidigital number, since it uses as much as digits as its factorization.

28288839 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9429616.

The product of its digits is 442368, while the sum is 48.

The square root of 28288839 is about 5318.7253172165. The cubic root of 28288839 is about 304.6994764470.

The spelling of 28288839 in words is "twenty-eight million, two hundred eighty-eight thousand, eight hundred thirty-nine".