28158223 has 4 divisors (see below), whose sum is σ = 28168840. Its totient is φ = 28147608.

The previous prime is 28158191. The next prime is 28158257. The reversal of 28158223 is 32285182.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 28158223 - 2⁵ = 28158191 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 (28159223) 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, 2461 + ... + 7897.

It is an arithmetic number, because the mean of its divisors is an integer number (7042210).

Almost surely, 2^28158223 is an apocalyptic number.

28158223 is a deficient number, since it is larger than the sum of its proper divisors (10617).

28158223 is an equidigital number, since it uses as much as digits as its factorization.

28158223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10616.

The product of its digits is 7680, while the sum is 31.

The square root of 28158223 is about 5306.4322289086. The cubic root of 28158223 is about 304.2297972504.

The spelling of 28158223 in words is "twenty-eight million, one hundred fifty-eight thousand, two hundred twenty-three".