28907889 has 4 divisors (see below), whose sum is σ = 38543856. Its totient is φ = 19271924.

The previous prime is 28907861. The next prime is 28907891. The reversal of 28907889 is 98870982.

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 a cyclic number.

It is not a de Polignac number, because 28907889 - 2¹¹ = 28905841 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28907819) 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, 4817979 + ... + 4817984.

It is an arithmetic number, because the mean of its divisors is an integer number (9635964).

Almost surely, 2^28907889 is an apocalyptic number.

It is an amenable number.

28907889 is a deficient number, since it is larger than the sum of its proper divisors (9635967).

28907889 is an equidigital number, since it uses as much as digits as its factorization.

28907889 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9635966.

The product of its (nonzero) digits is 580608, while the sum is 51.

The square root of 28907889 is about 5376.6057136450. The cubic root of 28907889 is about 306.9060569086.

The spelling of 28907889 in words is "twenty-eight million, nine hundred seven thousand, eight hundred eighty-nine".