28398923 has 4 divisors (see below), whose sum is σ = 32455920. Its totient is φ = 24341928.

The previous prime is 28398919. The next prime is 28398947. The reversal of 28398923 is 32989382.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 28398923 - 2² = 28398919 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28398913) 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, 2028488 + ... + 2028501.

It is an arithmetic number, because the mean of its divisors is an integer number (8113980).

Almost surely, 2^28398923 is an apocalyptic number.

28398923 is a deficient number, since it is larger than the sum of its proper divisors (4056997).

28398923 is an equidigital number, since it uses as much as digits as its factorization.

28398923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4056996.

The product of its digits is 186624, while the sum is 44.

The square root of 28398923 is about 5329.0639891073. The cubic root of 28398923 is about 305.0942036340.

The spelling of 28398923 in words is "twenty-eight million, three hundred ninety-eight thousand, nine hundred twenty-three".