28684563 has 4 divisors (see below), whose sum is σ = 38246088. Its totient is φ = 19123040.

The previous prime is 28684553. The next prime is 28684603. The reversal of 28684563 is 36548682.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28684563 - 2⁸ = 28684307 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28684553) 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, 4780758 + ... + 4780763.

It is an arithmetic number, because the mean of its divisors is an integer number (9561522).

Almost surely, 2^28684563 is an apocalyptic number.

28684563 is a deficient number, since it is larger than the sum of its proper divisors (9561525).

28684563 is an equidigital number, since it uses as much as digits as its factorization.

28684563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9561524.

The product of its digits is 276480, while the sum is 42.

The square root of 28684563 is about 5355.7971395489. The cubic root of 28684563 is about 306.1136853844.

The spelling of 28684563 in words is "twenty-eight million, six hundred eighty-four thousand, five hundred sixty-three".