28749728 has 24 divisors (see below), whose sum is σ = 64687392. Its totient is φ = 12321216.

The previous prime is 28749719. The next prime is 28749811. The reversal of 28749728 is 82794782.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63950 + ... + 64397.

It is an arithmetic number, because the mean of its divisors is an integer number (2695308).

Almost surely, 2^28749728 is an apocalyptic number.

28749728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

28749728 is an abundant number, since it is smaller than the sum of its proper divisors (35937664).

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

28749728 is a wasteful number, since it uses less digits than its factorization.

28749728 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128364 (or 128356 counting only the distinct ones).

The product of its digits is 451584, while the sum is 47.

The square root of 28749728 is about 5361.8772831910. The cubic root of 28749728 is about 306.3453176576.

The spelling of 28749728 in words is "twenty-eight million, seven hundred forty-nine thousand, seven hundred twenty-eight".