28656439 has 4 divisors (see below), whose sum is σ = 32750224. Its totient is φ = 24562656.

The previous prime is 28656409. The next prime is 28656451. The reversal of 28656439 is 93465682.

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 28656439 - 2⁷ = 28656311 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28656395 and 28656404.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28656409) 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, 2046882 + ... + 2046895.

It is an arithmetic number, because the mean of its divisors is an integer number (8187556).

Almost surely, 2^28656439 is an apocalyptic number.

28656439 is a deficient number, since it is larger than the sum of its proper divisors (4093785).

28656439 is an equidigital number, since it uses as much as digits as its factorization.

28656439 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4093784.

The product of its digits is 311040, while the sum is 43.

The square root of 28656439 is about 5353.1709294585. The cubic root of 28656439 is about 306.0136088327.

The spelling of 28656439 in words is "twenty-eight million, six hundred fifty-six thousand, four hundred thirty-nine".