28305899 has 4 divisors (see below), whose sum is σ = 28785720. Its totient is φ = 27826080.

The previous prime is 28305863. The next prime is 28305913. The reversal of 28305899 is 99850382.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 99850382 = 2 ⋅49925191.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28305899 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28305829) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 239822 + ... + 239939.

It is an arithmetic number, because the mean of its divisors is an integer number (7196430).

Almost surely, 2^28305899 is an apocalyptic number.

28305899 is a deficient number, since it is larger than the sum of its proper divisors (479821).

28305899 is an equidigital number, since it uses as much as digits as its factorization.

28305899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 479820.

The product of its (nonzero) digits is 155520, while the sum is 44.

The square root of 28305899 is about 5320.3288432201. The cubic root of 28305899 is about 304.7607153037.

The spelling of 28305899 in words is "twenty-eight million, three hundred five thousand, eight hundred ninety-nine".