28668556 has 24 divisors (see below), whose sum is σ = 57689856. Its totient is φ = 12210960.

The previous prime is 28668551. The next prime is 28668571. The reversal of 28668556 is 65586682.

It is a super-2 number, since 2×28668556² = 1643772206250272, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (28668551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1611 + ... + 7741.

It is an arithmetic number, because the mean of its divisors is an integer number (2403744).

Almost surely, 2^28668556 is an apocalyptic number.

It is an amenable number.

28668556 is an abundant number, since it is smaller than the sum of its proper divisors (29021300).

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

28668556 is a wasteful number, since it uses less digits than its factorization.

28668556 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6309 (or 6307 counting only the distinct ones).

The product of its digits is 691200, while the sum is 46.

The square root of 28668556 is about 5354.3025689626. The cubic root of 28668556 is about 306.0567340375.

The spelling of 28668556 in words is "twenty-eight million, six hundred sixty-eight thousand, five hundred fifty-six".