28728666 has 48 divisors (see below), whose sum is σ = 64022400. Its totient is φ = 9307584.

The previous prime is 28728649. The next prime is 28728673. The reversal of 28728666 is 66682782.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 126445 + ... + 126671.

It is an arithmetic number, because the mean of its divisors is an integer number (1333800).

Almost surely, 2^28728666 is an apocalyptic number.

28728666 is an abundant number, since it is smaller than the sum of its proper divisors (35293734).

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

28728666 is a wasteful number, since it uses less digits than its factorization.

28728666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 403 (or 400 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 28728666 is about 5359.9128724262. The cubic root of 28728666 is about 306.2704900354.

The spelling of 28728666 in words is "twenty-eight million, seven hundred twenty-eight thousand, six hundred sixty-six".