81065164 has 12 divisors (see below), whose sum is σ = 141954624. Its totient is φ = 40506704.

The previous prime is 81065161. The next prime is 81065167. The reversal of 81065164 is 46156018.

It is an interprime number because it is at equal distance from previous prime (81065161) and next prime (81065167).

It is not an unprimeable number, because it can be changed into a prime (81065161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1734 + ... + 12850.

It is an arithmetic number, because the mean of its divisors is an integer number (11829552).

Almost surely, 2^81065164 is an apocalyptic number.

It is an amenable number.

81065164 is a deficient number, since it is larger than the sum of its proper divisors (60889460).

81065164 is a wasteful number, since it uses less digits than its factorization.

81065164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12944 (or 12942 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 81065164 is about 9003.6194944033. The cubic root of 81065164 is about 432.7908680791.

The spelling of 81065164 in words is "eighty-one million, sixty-five thousand, one hundred sixty-four".