28308885 has 32 divisors (see below), whose sum is σ = 50758272. Its totient is φ = 13351680.

The previous prime is 28308881. The next prime is 28308887. The reversal of 28308885 is 58880382.

It is not a de Polignac number, because 28308885 - 2² = 28308881 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28308881) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3787 + ... + 8423.

It is an arithmetic number, because the mean of its divisors is an integer number (1586196).

Almost surely, 2^28308885 is an apocalyptic number.

It is an amenable number.

28308885 is a deficient number, since it is larger than the sum of its proper divisors (22449387).

28308885 is a wasteful number, since it uses less digits than its factorization.

28308885 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4693.

The product of its (nonzero) digits is 122880, while the sum is 42.

The square root of 28308885 is about 5320.6094575716. The cubic root of 28308885 is about 304.7714313680.

The spelling of 28308885 in words is "twenty-eight million, three hundred eight thousand, eight hundred eighty-five".