28576821 has 16 divisors (see below), whose sum is σ = 46895744. Its totient is φ = 15073344.

The previous prime is 28576819. The next prime is 28576829. The reversal of 28576821 is 12867582.

It is not a de Polignac number, because 28576821 - 2¹ = 28576819 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a self number, because there is not a number n which added to its sum of digits gives 28576821.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28576829) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52066 + ... + 52611.

It is an arithmetic number, because the mean of its divisors is an integer number (2930984).

Almost surely, 2^28576821 is an apocalyptic number.

28576821 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

28576821 is a deficient number, since it is larger than the sum of its proper divisors (18318923).

28576821 is a wasteful number, since it uses less digits than its factorization.

28576821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 104700.

The product of its digits is 53760, while the sum is 39.

The square root of 28576821 is about 5345.7292299554. The cubic root of 28576821 is about 305.7299402932.

The spelling of 28576821 in words is "twenty-eight million, five hundred seventy-six thousand, eight hundred twenty-one".