28320656 has 80 divisors (see below), whose sum is σ = 68995584. Its totient is φ = 10962432.

The previous prime is 28320647. The next prime is 28320661. The reversal of 28320656 is 65602382.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 76985 + ... + 77351.

Almost surely, 2^28320656 is an apocalyptic number.

28320656 is a gapful number since it is divisible by the number (26) 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 28320656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34497792).

28320656 is an abundant number, since it is smaller than the sum of its proper divisors (40674928).

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

28320656 is a wasteful number, since it uses less digits than its factorization.

28320656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 448 (or 442 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 28320656 is about 5321.7155128774. The cubic root of 28320656 is about 304.8136674293.

The spelling of 28320656 in words is "twenty-eight million, three hundred twenty thousand, six hundred fifty-six".