28005566 has 16 divisors (see below), whose sum is σ = 42577920. Its totient is φ = 13814520.

The previous prime is 28005557. The next prime is 28005569. The reversal of 28005566 is 66550082.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28005569) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 63575 + ... + 64013.

It is an arithmetic number, because the mean of its divisors is an integer number (2661120).

Almost surely, 2^28005566 is an apocalyptic number.

28005566 is a deficient number, since it is larger than the sum of its proper divisors (14572354).

28005566 is a wasteful number, since it uses less digits than its factorization.

28005566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 799.

The product of its (nonzero) digits is 14400, while the sum is 32.

The square root of 28005566 is about 5292.0285335588. The cubic root of 28005566 is about 303.6790168714.

The spelling of 28005566 in words is "twenty-eight million, five thousand, five hundred sixty-six".