28091564 has 6 divisors (see below), whose sum is σ = 49160244. Its totient is φ = 14045780.

The previous prime is 28091563. The next prime is 28091573. The reversal of 28091564 is 46519082.

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

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3511442 + ... + 3511449.

It is an arithmetic number, because the mean of its divisors is an integer number (8193374).

Almost surely, 2^28091564 is an apocalyptic number.

It is an amenable number.

28091564 is a deficient number, since it is larger than the sum of its proper divisors (21068680).

28091564 is a wasteful number, since it uses less digits than its factorization.

28091564 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7022895 (or 7022893 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 28091564 is about 5300.1475451161. The cubic root of 28091564 is about 303.9895396909.

The spelling of 28091564 in words is "twenty-eight million, ninety-one thousand, five hundred sixty-four".