28643328 has 208 divisors, whose sum is σ = 99602560. Its totient is φ = 7962624.

The previous prime is 28643311. The next prime is 28643357. The reversal of 28643328 is 82334682.

28643328 is a `hidden beast` number, since 2 + 8 + 643 + 3 + 2 + 8 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a nude number because it is divisible by every one of its digits and also a Zuckerman number because it is divisible by the product of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 28643292 and 28643301.

It is a congruent number.

It is an unprimeable number.

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 15 ways as a sum of consecutive naturals, for example, 774126 + ... + 774162.

Almost surely, 2^28643328 is an apocalyptic number.

28643328 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 28643328, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (49801280).

28643328 is an abundant number, since it is smaller than the sum of its proper divisors (70959232).

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

28643328 is an equidigital number, since it uses as much as digits as its factorization.

28643328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 77 (or 49 counting only the distinct ones).

The product of its digits is 55296, while the sum is 36.

The square root of 28643328 is about 5351.9461880703. The cubic root of 28643328 is about 305.9669322206.

The spelling of 28643328 in words is "twenty-eight million, six hundred forty-three thousand, three hundred twenty-eight".