28666 has 8 divisors (see below), whose sum is σ = 46944. Its totient is φ = 13020.

The previous prime is 28663. The next prime is 28669. The reversal of 28666 is 66682.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (28663) and next prime (28669).

It is a sphenic number, since it is the product of 3 distinct primes.

28666 is a modest number, since divided by 666 gives 28 as remainder.

It is a nialpdrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (28661) 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, 630 + ... + 673.

It is an arithmetic number, because the mean of its divisors is an integer number (5868).

2²⁸⁶⁶⁶ is an apocalyptic number.

28666 is the 91-st centered heptagonal number.

28666 is a deficient number, since it is larger than the sum of its proper divisors (18278).

28666 is a wasteful number, since it uses less digits than its factorization.

28666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1316.

The product of its digits is 3456, while the sum is 28.

The square root of 28666 is about 169.3103658965. The cubic root of 28666 is about 30.6047638076.

It can be divided in two parts, 2 and 8666, that added together give a palindrome (8668).

The spelling of 28666 in words is "twenty-eight thousand, six hundred sixty-six".