28128323 has 4 divisors (see below), whose sum is σ = 28146288. Its totient is φ = 28110360.

The previous prime is 28128313. The next prime is 28128329. The reversal of 28128323 is 32382182.

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 28128323 - 2⁴ = 28128307 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28128329) 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, 6383 + ... + 9848.

It is an arithmetic number, because the mean of its divisors is an integer number (7036572).

Almost surely, 2^28128323 is an apocalyptic number.

28128323 is a deficient number, since it is larger than the sum of its proper divisors (17965).

28128323 is a wasteful number, since it uses less digits than its factorization.

28128323 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17964.

The product of its digits is 4608, while the sum is 29.

The square root of 28128323 is about 5303.6141450901. The cubic root of 28128323 is about 304.1220762891.

The spelling of 28128323 in words is "twenty-eight million, one hundred twenty-eight thousand, three hundred twenty-three".