81965163 has 16 divisors (see below), whose sum is σ = 125048576. Its totient is φ = 46781280.

The previous prime is 81965159. The next prime is 81965179. The reversal of 81965163 is 36156918.

It is not a de Polignac number, because 81965163 - 2² = 81965159 is a prime.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81965153) 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, 21168 + ... + 24738.

It is an arithmetic number, because the mean of its divisors is an integer number (7815536).

Almost surely, 2^81965163 is an apocalyptic number.

81965163 is a deficient number, since it is larger than the sum of its proper divisors (43083413).

81965163 is a wasteful number, since it uses less digits than its factorization.

81965163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4674.

The product of its digits is 38880, while the sum is 39.

The square root of 81965163 is about 9053.4613822560. The cubic root of 81965163 is about 434.3866159998.

It can be divided in two parts, 81965 and 163, that added together give a palindrome (82128).

The spelling of 81965163 in words is "eighty-one million, nine hundred sixty-five thousand, one hundred sixty-three".