28709328 has 80 divisors (see below), whose sum is σ = 79387776. Its totient is φ = 8908800.

The previous prime is 28709327. The next prime is 28709357. The reversal of 28709328 is 82390782.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28709321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 123100 + ... + 123332.

Almost surely, 2^28709328 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 28709328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (39693888).

28709328 is an abundant number, since it is smaller than the sum of its proper divisors (50678448).

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

28709328 is a wasteful number, since it uses less digits than its factorization.

28709328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 412 (or 406 counting only the distinct ones).

The product of its (nonzero) digits is 48384, while the sum is 39.

The square root of 28709328 is about 5358.1086215194. The cubic root of 28709328 is about 306.2017551102.

The spelling of 28709328 in words is "twenty-eight million, seven hundred nine thousand, three hundred twenty-eight".