28091566 has 16 divisors (see below), whose sum is σ = 42865200. Its totient is φ = 13805440.

The previous prime is 28091563. The next prime is 28091573. The reversal of 28091566 is 66519082.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28091561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31446 + ... + 32326.

It is an arithmetic number, because the mean of its divisors is an integer number (2679075).

Almost surely, 2^28091566 is an apocalyptic number.

28091566 is a deficient number, since it is larger than the sum of its proper divisors (14773634).

28091566 is a wasteful number, since it uses less digits than its factorization.

28091566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1139.

The product of its (nonzero) digits is 25920, while the sum is 37.

The square root of 28091566 is about 5300.1477337901. The cubic root of 28091566 is about 303.9895469051.

The spelling of 28091566 in words is "twenty-eight million, ninety-one thousand, five hundred sixty-six".