28809923 has 4 divisors (see below), whose sum is σ = 29133720. Its totient is φ = 28486128.

The previous prime is 28809901. The next prime is 28809929. The reversal of 28809923 is 32990882.

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 28809923 - 2⁸ = 28809667 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28809929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 161765 + ... + 161942.

It is an arithmetic number, because the mean of its divisors is an integer number (7283430).

Almost surely, 2^28809923 is an apocalyptic number.

28809923 is a deficient number, since it is larger than the sum of its proper divisors (323797).

28809923 is an equidigital number, since it uses as much as digits as its factorization.

28809923 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 323796.

The product of its (nonzero) digits is 62208, while the sum is 41.

The square root of 28809923 is about 5367.4875873168. The cubic root of 28809923 is about 306.5589730284.

The spelling of 28809923 in words is "twenty-eight million, eight hundred nine thousand, nine hundred twenty-three".