28724688 has 60 divisors (see below), whose sum is σ = 82276480. Its totient is φ = 9350208.

The previous prime is 28724687. The next prime is 28724699. The reversal of 28724688 is 88642782.

It is a happy number.

It is a nialpdrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28724687) 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 11 ways as a sum of consecutive naturals, for example, 3873 + ... + 8511.

Almost surely, 2^28724688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28724688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41138240).

28724688 is an abundant number, since it is smaller than the sum of its proper divisors (53551792).

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

28724688 is a wasteful number, since it uses less digits than its factorization.

28724688 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4696 (or 4687 counting only the distinct ones).

The product of its digits is 344064, while the sum is 45.

The square root of 28724688 is about 5359.5417714577. The cubic root of 28724688 is about 306.2563531654.

The spelling of 28724688 in words is "twenty-eight million, seven hundred twenty-four thousand, six hundred eighty-eight".