28728886 has 8 divisors (see below), whose sum is σ = 44967024. Its totient is φ = 13739880.

The previous prime is 28728881. The next prime is 28728911. The reversal of 28728886 is 68882782.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28728881) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 312225 + ... + 312316.

It is an arithmetic number, because the mean of its divisors is an integer number (5620878).

Almost surely, 2^28728886 is an apocalyptic number.

28728886 is a deficient number, since it is larger than the sum of its proper divisors (16238138).

28728886 is a wasteful number, since it uses less digits than its factorization.

28728886 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 624566.

The product of its digits is 688128, while the sum is 49.

The square root of 28728886 is about 5359.9333951086. The cubic root of 28728886 is about 306.2712718252.

The spelling of 28728886 in words is "twenty-eight million, seven hundred twenty-eight thousand, eight hundred eighty-six".