28904989 has 4 divisors (see below), whose sum is σ = 29837440. Its totient is φ = 27972540.

The previous prime is 28904977. The next prime is 28905053. The reversal of 28904989 is 98940982.

It is a happy number.

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 28904989 - 2¹³ = 28896797 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28904969) 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, 466179 + ... + 466240.

It is an arithmetic number, because the mean of its divisors is an integer number (7459360).

Almost surely, 2^28904989 is an apocalyptic number.

It is an amenable number.

28904989 is a deficient number, since it is larger than the sum of its proper divisors (932451).

28904989 is an equidigital number, since it uses as much as digits as its factorization.

28904989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 932450.

The product of its (nonzero) digits is 373248, while the sum is 49.

The square root of 28904989 is about 5376.3360200047. The cubic root of 28904989 is about 306.8957937663.

The spelling of 28904989 in words is "twenty-eight million, nine hundred four thousand, nine hundred eighty-nine".