28489009 has 4 divisors (see below), whose sum is σ = 28624240. Its totient is φ = 28353780.

The previous prime is 28489007. The next prime is 28489057. The reversal of 28489009 is 90098482.

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, and also an emirpimes, since its reverse is a distinct semiprime: 90098482 = 2 ⋅45049241.

It is a cyclic number.

It is not a de Polignac number, because 28489009 - 2¹ = 28489007 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28489007) 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, 67299 + ... + 67720.

It is an arithmetic number, because the mean of its divisors is an integer number (7156060).

Almost surely, 2^28489009 is an apocalyptic number.

It is an amenable number.

28489009 is a deficient number, since it is larger than the sum of its proper divisors (135231).

28489009 is a wasteful number, since it uses less digits than its factorization.

28489009 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 135230.

The product of its (nonzero) digits is 41472, while the sum is 40.

The square root of 28489009 is about 5337.5096252841. The cubic root of 28489009 is about 305.4164659200.

The spelling of 28489009 in words is "twenty-eight million, four hundred eighty-nine thousand, nine".