28091899 has 16 divisors (see below), whose sum is σ = 32446080. Its totient is φ = 24053760.

The previous prime is 28091897. The next prime is 28091927. The reversal of 28091899 is 99819082.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 28091899 - 2¹ = 28091897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28091893) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 53452 + ... + 53974.

It is an arithmetic number, because the mean of its divisors is an integer number (2027880).

Almost surely, 2^28091899 is an apocalyptic number.

28091899 is a deficient number, since it is larger than the sum of its proper divisors (4354181).

28091899 is a wasteful number, since it uses less digits than its factorization.

28091899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 810.

The product of its (nonzero) digits is 93312, while the sum is 46.

The square root of 28091899 is about 5300.1791479157. The cubic root of 28091899 is about 303.9907480737.

The spelling of 28091899 in words is "twenty-eight million, ninety-one thousand, eight hundred ninety-nine".