28723866 has 8 divisors (see below), whose sum is σ = 57447744. Its totient is φ = 9574620.

The previous prime is 28723853. The next prime is 28723867. The reversal of 28723866 is 66832782.

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

28723866 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (28723867) 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 3 ways as a sum of consecutive naturals, for example, 2393650 + ... + 2393661.

It is an arithmetic number, because the mean of its divisors is an integer number (7180968).

Almost surely, 2^28723866 is an apocalyptic number.

28723866 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

28723866 is a wasteful number, since it uses less digits than its factorization.

28723866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4787316.

The product of its digits is 193536, while the sum is 42.

The square root of 28723866 is about 5359.4650852487. The cubic root of 28723866 is about 306.2534318094.

The spelling of 28723866 in words is "twenty-eight million, seven hundred twenty-three thousand, eight hundred sixty-six".