28198423 has 4 divisors (see below), whose sum is σ = 30761928. Its totient is φ = 25634920.

The previous prime is 28198421. The next prime is 28198453. The reversal of 28198423 is 32489182.

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 28198423 - 2¹ = 28198421 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 (28198421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1281736 + ... + 1281757.

It is an arithmetic number, because the mean of its divisors is an integer number (7690482).

Almost surely, 2^28198423 is an apocalyptic number.

28198423 is a deficient number, since it is larger than the sum of its proper divisors (2563505).

28198423 is a wasteful number, since it uses less digits than its factorization.

28198423 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2563504.

The product of its digits is 27648, while the sum is 37.

The square root of 28198423 is about 5310.2187337246. The cubic root of 28198423 is about 304.3745059844.

The spelling of 28198423 in words is "twenty-eight million, one hundred ninety-eight thousand, four hundred twenty-three".