28008569 has 4 divisors (see below), whose sum is σ = 28604544. Its totient is φ = 27412596.

The previous prime is 28008559. The next prime is 28008601. The reversal of 28008569 is 96580082.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28008569 is a prime.

It is a super-2 number, since 2×28008569² = 1568959874855522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28008509) 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, 297917 + ... + 298010.

It is an arithmetic number, because the mean of its divisors is an integer number (7151136).

Almost surely, 2^28008569 is an apocalyptic number.

It is an amenable number.

28008569 is a deficient number, since it is larger than the sum of its proper divisors (595975).

28008569 is an equidigital number, since it uses as much as digits as its factorization.

28008569 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 595974.

The product of its (nonzero) digits is 34560, while the sum is 38.

The square root of 28008569 is about 5292.3122545821. The cubic root of 28008569 is about 303.6898708506.

The spelling of 28008569 in words is "twenty-eight million, eight thousand, five hundred sixty-nine".