28189728 has 192 divisors, whose sum is σ = 96768000. Its totient is φ = 7817472.

The previous prime is 28189717. The next prime is 28189751. The reversal of 28189728 is 82798182.

It is a happy number.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 356793 + ... + 356871.

It is an arithmetic number, because the mean of its divisors is an integer number (504000).

Almost surely, 2^28189728 is an apocalyptic number.

28189728 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 28189728, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (48384000).

28189728 is an abundant number, since it is smaller than the sum of its proper divisors (68578272).

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

28189728 is a wasteful number, since it uses less digits than its factorization.

28189728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 164 (or 150 counting only the distinct ones).

The product of its digits is 129024, while the sum is 45.

The square root of 28189728 is about 5309.3999660979. The cubic root of 28189728 is about 304.3432180834.

It can be divided in two parts, 281 and 89728, that added together give a palindrome (90009).

The spelling of 28189728 in words is "twenty-eight million, one hundred eighty-nine thousand, seven hundred twenty-eight".