28387328 has 48 divisors (see below), whose sum is σ = 57788640. Its totient is φ = 13938688.

The previous prime is 28387321. The next prime is 28387339. The reversal of 28387328 is 82378382.

Its product of digits (129024) is a multiple of the sum of its prime divisors (252).

It is not an unprimeable number, because it can be changed into a prime (28387321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 169901 + ... + 170067.

It is an arithmetic number, because the mean of its divisors is an integer number (1203930).

Almost surely, 2^28387328 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 28387328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28894320).

28387328 is an abundant number, since it is smaller than the sum of its proper divisors (29401312).

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

28387328 is an equidigital number, since it uses as much as digits as its factorization.

28387328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 272 (or 252 counting only the distinct ones).

The product of its digits is 129024, while the sum is 41.

The square root of 28387328 is about 5327.9759759218. The cubic root of 28387328 is about 305.0526756642.

The spelling of 28387328 in words is "twenty-eight million, three hundred eighty-seven thousand, three hundred twenty-eight".