28239728 has 20 divisors (see below), whose sum is σ = 59688888. Its totient is φ = 12836160.

The previous prime is 28239727. The next prime is 28239779. The reversal of 28239728 is 82793282.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28239727) 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, 80051 + ... + 80402.

Almost surely, 2^28239728 is an apocalyptic number.

It is an amenable number.

28239728 is an abundant number, since it is smaller than the sum of its proper divisors (31449160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

28239728 is a wasteful number, since it uses less digits than its factorization.

28239728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 160472 (or 160466 counting only the distinct ones).

The product of its digits is 96768, while the sum is 41.

The square root of 28239728 is about 5314.1065100353. The cubic root of 28239728 is about 304.5230492249.

The spelling of 28239728 in words is "twenty-eight million, two hundred thirty-nine thousand, seven hundred twenty-eight".