81384165 has 48 divisors (see below), whose sum is σ = 145873728. Its totient is φ = 41948928.

The previous prime is 81384161. The next prime is 81384197. The reversal of 81384165 is 56148318.

It is not a de Polignac number, because 81384165 - 2² = 81384161 is a prime.

It is a hoax number, since the sum of its digits (36) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81384161) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 264942 + ... + 265248.

It is an arithmetic number, because the mean of its divisors is an integer number (3039036).

Almost surely, 2^81384165 is an apocalyptic number.

It is an amenable number.

81384165 is a deficient number, since it is larger than the sum of its proper divisors (64489563).

81384165 is a wasteful number, since it uses less digits than its factorization.

81384165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 498 (or 495 counting only the distinct ones).

The product of its digits is 23040, while the sum is 36.

The square root of 81384165 is about 9021.3172541486. The cubic root of 81384165 is about 433.3578194579.

The spelling of 81384165 in words is "eighty-one million, three hundred eighty-four thousand, one hundred sixty-five".