28193089 has 4 divisors (see below), whose sum is σ = 29851524. Its totient is φ = 26534656.

The previous prime is 28193071. The next prime is 28193119. The reversal of 28193089 is 98039182.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 21344400 + 6848689 = 4620^2 + 2617^2 .

It is a cyclic number.

It is not a de Polignac number, because 28193089 - 2¹⁷ = 28062017 is a prime.

It is a Smith number, since the sum of its digits (40) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (28193069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 829192 + ... + 829225.

It is an arithmetic number, because the mean of its divisors is an integer number (7462881).

Almost surely, 2^28193089 is an apocalyptic number.

It is an amenable number.

28193089 is a deficient number, since it is larger than the sum of its proper divisors (1658435).

28193089 is a wasteful number, since it uses less digits than its factorization.

28193089 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1658434.

The product of its (nonzero) digits is 31104, while the sum is 40.

The square root of 28193089 is about 5309.7164707732. The cubic root of 28193089 is about 304.3553129962.

The spelling of 28193089 in words is "twenty-eight million, one hundred ninety-three thousand, eighty-nine".