28239489 has 8 divisors (see below), whose sum is σ = 41836320. Its totient is φ = 18826308.

The previous prime is 28239487. The next prime is 28239509. The reversal of 28239489 is 98493282.

It is not a de Polignac number, because 28239489 - 2¹ = 28239487 is a prime.

It is a super-2 number, since 2×28239489² = 1594937477962242, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28239487) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 522927 + ... + 522980.

It is an arithmetic number, because the mean of its divisors is an integer number (5229540).

Almost surely, 2^28239489 is an apocalyptic number.

It is an amenable number.

28239489 is a deficient number, since it is larger than the sum of its proper divisors (13596831).

28239489 is a wasteful number, since it uses less digits than its factorization.

28239489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1045916 (or 1045910 counting only the distinct ones).

The product of its digits is 248832, while the sum is 45.

The square root of 28239489 is about 5314.0840226703. The cubic root of 28239489 is about 304.5221901371.

The spelling of 28239489 in words is "twenty-eight million, two hundred thirty-nine thousand, four hundred eighty-nine".