28091666 has 8 divisors (see below), whose sum is σ = 42160944. Its totient is φ = 14038020.

The previous prime is 28091663. The next prime is 28091677. The reversal of 28091666 is 66619082.

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

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28091663) 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, 3101 + ... + 8111.

It is an arithmetic number, because the mean of its divisors is an integer number (5270118).

Almost surely, 2^28091666 is an apocalyptic number.

28091666 is a deficient number, since it is larger than the sum of its proper divisors (14069278).

28091666 is a wasteful number, since it uses less digits than its factorization.

28091666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7816.

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 28091666 is about 5300.1571674810. The cubic root of 28091666 is about 303.9899076174.

The spelling of 28091666 in words is "twenty-eight million, ninety-one thousand, six hundred sixty-six".