28268239 has 4 divisors (see below), whose sum is σ = 28801656. Its totient is φ = 27734824.

The previous prime is 28268237. The next prime is 28268267. The reversal of 28268239 is 93286282.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 93286282 = 2 ⋅46643141.

It is a cyclic number.

It is not a de Polignac number, because 28268239 - 2¹ = 28268237 is a prime.

It is a super-2 number, since 2×28268239² = 1598186672322242, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28268231) 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, 266629 + ... + 266734.

It is an arithmetic number, because the mean of its divisors is an integer number (7200414).

Almost surely, 2^28268239 is an apocalyptic number.

28268239 is a deficient number, since it is larger than the sum of its proper divisors (533417).

28268239 is an equidigital number, since it uses as much as digits as its factorization.

28268239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 533416.

The product of its digits is 82944, while the sum is 40.

The square root of 28268239 is about 5316.7884103094. The cubic root of 28268239 is about 304.6254975252.

The spelling of 28268239 in words is "twenty-eight million, two hundred sixty-eight thousand, two hundred thirty-nine".