81168605 has 16 divisors (see below), whose sum is σ = 112662144. Its totient is φ = 54985920.

The previous prime is 81168569. The next prime is 81168611. The reversal of 81168605 is 50686118.

It is not a de Polignac number, because 81168605 - 2¹⁶ = 81103069 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (35).

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11066 + ... + 16875.

It is an arithmetic number, because the mean of its divisors is an integer number (7041384).

Almost surely, 2^81168605 is an apocalyptic number.

It is an amenable number.

81168605 is a deficient number, since it is larger than the sum of its proper divisors (31493539).

81168605 is a wasteful number, since it uses less digits than its factorization.

81168605 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28036.

The product of its (nonzero) digits is 11520, while the sum is 35.

The square root of 81168605 is about 9009.3620750861. The cubic root of 81168605 is about 432.9748735124.

The spelling of 81168605 in words is "eighty-one million, one hundred sixty-eight thousand, six hundred five".