28712728 has 48 divisors (see below), whose sum is σ = 62443800. Its totient is φ = 12272640.

The previous prime is 28712713. The next prime is 28712753. The reversal of 28712728 is 82721782.

It is a happy number.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

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, 24868 + ... + 25996.

Almost surely, 2^28712728 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 28712728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31221900).

28712728 is an abundant number, since it is smaller than the sum of its proper divisors (33731072).

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

28712728 is a wasteful number, since it uses less digits than its factorization.

28712728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1180 (or 1159 counting only the distinct ones).

The product of its digits is 25088, while the sum is 37.

The square root of 28712728 is about 5358.4258882623. The cubic root of 28712728 is about 306.2138422951.

The spelling of 28712728 in words is "twenty-eight million, seven hundred twelve thousand, seven hundred twenty-eight".