81168009 has 16 divisors (see below), whose sum is σ = 116730432. Its totient is φ = 49871808.

The previous prime is 81168007. The next prime is 81168083. The reversal of 81168009 is 90086118.

It is not a de Polignac number, because 81168009 - 2¹ = 81168007 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81168001) 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, 33259 + ... + 35615.

It is an arithmetic number, because the mean of its divisors is an integer number (7295652).

Almost surely, 2^81168009 is an apocalyptic number.

It is an amenable number.

81168009 is a deficient number, since it is larger than the sum of its proper divisors (35562423).

81168009 is a wasteful number, since it uses less digits than its factorization.

81168009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3256.

The product of its (nonzero) digits is 3456, while the sum is 33.

The square root of 81168009 is about 9009.3289983217. The cubic root of 81168009 is about 432.9738137691.

The spelling of 81168009 in words is "eighty-one million, one hundred sixty-eight thousand, nine".