28129089 has 4 divisors (see below), whose sum is σ = 37505456. Its totient is φ = 18752724.

The previous prime is 28129021. The next prime is 28129091. The reversal of 28129089 is 98092182.

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 not a de Polignac number, because 28129089 - 2⁸ = 28128833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28129789) 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, 4688179 + ... + 4688184.

It is an arithmetic number, because the mean of its divisors is an integer number (9376364).

Almost surely, 2^28129089 is an apocalyptic number.

It is an amenable number.

28129089 is a deficient number, since it is larger than the sum of its proper divisors (9376367).

28129089 is an equidigital number, since it uses as much as digits as its factorization.

28129089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9376366.

The product of its (nonzero) digits is 20736, while the sum is 39.

The square root of 28129089 is about 5303.6863595051. The cubic root of 28129089 is about 304.1248369157.

The spelling of 28129089 in words is "twenty-eight million, one hundred twenty-nine thousand, eighty-nine".