28166 has 4 divisors (see below), whose sum is σ = 42252. Its totient is φ = 14082.

The previous prime is 28163. The next prime is 28181. The reversal of 28166 is 66182.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 66182 = 2 ⋅33091.

It is a Curzon number.

It is a nialpdrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28163) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7040 + ... + 7043.

It is an arithmetic number, because the mean of its divisors is an integer number (10563).

2²⁸¹⁶⁶ is an apocalyptic number.

28166 is a deficient number, since it is larger than the sum of its proper divisors (14086).

28166 is a wasteful number, since it uses less digits than its factorization.

28166 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14085.

The product of its digits is 576, while the sum is 23.

The square root of 28166 is about 167.8272921786. The cubic root of 28166 is about 30.4257803011.

The spelling of 28166 in words is "twenty-eight thousand, one hundred sixty-six".