28168009 has 2 divisors, whose sum is σ = 28168010. Its totient is φ = 28168008.

The previous prime is 28167947. The next prime is 28168037. The reversal of 28168009 is 90086182.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15721225 + 12446784 = 3965^2 + 3528^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28168009 is a prime.

It is not a weakly prime, because it can be changed into another prime (28168079) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14084004 + 14084005.

It is an arithmetic number, because the mean of its divisors is an integer number (14084005).

Almost surely, 2^28168009 is an apocalyptic number.

It is an amenable number.

28168009 is a deficient number, since it is larger than the sum of its proper divisors (1).

28168009 is an equidigital number, since it uses as much as digits as its factorization.

28168009 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 6912, while the sum is 34.

The square root of 28168009 is about 5307.3542372825. The cubic root of 28168009 is about 304.2650367844.

The spelling of 28168009 in words is "twenty-eight million, one hundred sixty-eight thousand, nine".