28438223 has 4 divisors (see below), whose sum is σ = 31023528. Its totient is φ = 25852920.

The previous prime is 28438213. The next prime is 28438247. The reversal of 28438223 is 32283482.

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 28438223 - 2⁶ = 28438159 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28438223.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28438213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1292636 + ... + 1292657.

It is an arithmetic number, because the mean of its divisors is an integer number (7755882).

Almost surely, 2^28438223 is an apocalyptic number.

28438223 is a deficient number, since it is larger than the sum of its proper divisors (2585305).

28438223 is a wasteful number, since it uses less digits than its factorization.

28438223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2585304.

The product of its digits is 18432, while the sum is 32.

The square root of 28438223 is about 5332.7500410201. The cubic root of 28438223 is about 305.2348741746.

The spelling of 28438223 in words is "twenty-eight million, four hundred thirty-eight thousand, two hundred twenty-three".