28223999 has 4 divisors (see below), whose sum is σ = 28269360. Its totient is φ = 28178640.

The previous prime is 28223941. The next prime is 28224011. The reversal of 28223999 is 99932282.

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 28223999 - 2²⁴ = 11446783 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28223929) 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, 21734 + ... + 22995.

It is an arithmetic number, because the mean of its divisors is an integer number (7067340).

Almost surely, 2^28223999 is an apocalyptic number.

28223999 is a deficient number, since it is larger than the sum of its proper divisors (45361).

28223999 is an equidigital number, since it uses as much as digits as its factorization.

28223999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45360.

The product of its digits is 139968, while the sum is 44.

The square root of 28223999 is about 5312.6263749675. The cubic root of 28223999 is about 304.4665008450.

The spelling of 28223999 in words is "twenty-eight million, two hundred twenty-three thousand, nine hundred ninety-nine".