28066393 has 4 divisors (see below), whose sum is σ = 28209060. Its totient is φ = 27923728.

The previous prime is 28066373. The next prime is 28066399. The reversal of 28066393 is 39366082.

It is a happy number.

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 20684304 + 7382089 = 4548^2 + 2717^2 .

It is a cyclic number.

It is not a de Polignac number, because 28066393 - 2⁵ = 28066361 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28066399) 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, 71038 + ... + 71431.

It is an arithmetic number, because the mean of its divisors is an integer number (7052265).

Almost surely, 2^28066393 is an apocalyptic number.

It is an amenable number.

28066393 is a deficient number, since it is larger than the sum of its proper divisors (142667).

28066393 is a wasteful number, since it uses less digits than its factorization.

28066393 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 142666.

The product of its (nonzero) digits is 46656, while the sum is 37.

The square root of 28066393 is about 5297.7724564198. The cubic root of 28066393 is about 303.8987175584.

The spelling of 28066393 in words is "twenty-eight million, sixty-six thousand, three hundred ninety-three".