28688089 has 2 divisors, whose sum is σ = 28688090. Its totient is φ = 28688088.

The previous prime is 28688087. The next prime is 28688111. The reversal of 28688089 is 98088682.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 24206400 + 4481689 = 4920^2 + 2117^2 .

It is a cyclic number.

It is not a de Polignac number, because 28688089 - 2¹ = 28688087 is a prime.

Together with 28688087, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (28688087) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14344044 + 14344045.

It is an arithmetic number, because the mean of its divisors is an integer number (14344045).

Almost surely, 2^28688089 is an apocalyptic number.

It is an amenable number.

28688089 is a deficient number, since it is larger than the sum of its proper divisors (1).

28688089 is an equidigital number, since it uses as much as digits as its factorization.

28688089 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 442368, while the sum is 49.

The square root of 28688089 is about 5356.1263054562. The cubic root of 28688089 is about 306.1262277012.

The spelling of 28688089 in words is "twenty-eight million, six hundred eighty-eight thousand, eighty-nine".