28328728 has 8 divisors (see below), whose sum is σ = 53116380. Its totient is φ = 14164360.

The previous prime is 28328693. The next prime is 28328731. The reversal of 28328728 is 82782382.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (8).

It is a congruent number.

It is an unprimeable number.

It is an upside-down number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1770538 + ... + 1770553.

Almost surely, 2^28328728 is an apocalyptic number.

It is an amenable number.

28328728 is a deficient number, since it is larger than the sum of its proper divisors (24787652).

28328728 is a wasteful number, since it uses less digits than its factorization.

28328728 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3541097 (or 3541093 counting only the distinct ones).

The product of its digits is 86016, while the sum is 40.

The square root of 28328728 is about 5322.4738609034. The cubic root of 28328728 is about 304.8426241761.

The spelling of 28328728 in words is "twenty-eight million, three hundred twenty-eight thousand, seven hundred twenty-eight".