28477728 has 72 divisors (see below), whose sum is σ = 82361916. Its totient is φ = 9331200.

The previous prime is 28477717. The next prime is 28477733. The reversal of 28477728 is 82777482.

It can be written as a sum of positive squares in 2 ways, for example, as 27751824 + 725904 = 5268^2 + 852^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a nialpdrome in base 12.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 16758 + ... + 18378.

Almost surely, 2^28477728 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 28477728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (41180958).

28477728 is an abundant number, since it is smaller than the sum of its proper divisors (53884188).

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

28477728 is a wasteful number, since it uses less digits than its factorization.

28477728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1698 (or 1687 counting only the distinct ones).

The product of its digits is 351232, while the sum is 45.

The square root of 28477728 is about 5336.4527544053. The cubic root of 28477728 is about 305.3761479385.

The spelling of 28477728 in words is "twenty-eight million, four hundred seventy-seven thousand, seven hundred twenty-eight".