28809489 has 4 divisors (see below), whose sum is σ = 38412656. Its totient is φ = 19206324.

The previous prime is 28809481. The next prime is 28809533. The reversal of 28809489 is 98490882.

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 28809489 - 2³ = 28809481 is a prime.

It is a super-2 number, since 2×28809489² = 1659973312882242, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28809481) 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, 4801579 + ... + 4801584.

It is an arithmetic number, because the mean of its divisors is an integer number (9603164).

Almost surely, 2^28809489 is an apocalyptic number.

It is an amenable number.

28809489 is a deficient number, since it is larger than the sum of its proper divisors (9603167).

28809489 is an equidigital number, since it uses as much as digits as its factorization.

28809489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9603166.

The product of its (nonzero) digits is 331776, while the sum is 48.

The square root of 28809489 is about 5367.4471585662. The cubic root of 28809489 is about 306.5574336600.

The spelling of 28809489 in words is "twenty-eight million, eight hundred nine thousand, four hundred eighty-nine".