28164409 has 16 divisors (see below), whose sum is σ = 34951168. Its totient is φ = 22099392.

The previous prime is 28164361. The next prime is 28164413. The reversal of 28164409 is 90446182.

It is not a de Polignac number, because 28164409 - 2⁹ = 28163897 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28164419) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10339 + ... + 12775.

It is an arithmetic number, because the mean of its divisors is an integer number (2184448).

Almost surely, 2^28164409 is an apocalyptic number.

It is an amenable number.

28164409 is a deficient number, since it is larger than the sum of its proper divisors (6786759).

28164409 is a wasteful number, since it uses less digits than its factorization.

28164409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2584.

The product of its (nonzero) digits is 13824, while the sum is 34.

The square root of 28164409 is about 5307.0150744086. The cubic root of 28164409 is about 304.2520740791.

It can be divided in two parts, 2816 and 4409, that added together give a square (7225 = 85²).

The spelling of 28164409 in words is "twenty-eight million, one hundred sixty-four thousand, four hundred nine".