81384732605 has 64 divisors (see below), whose sum is σ = 115878297600. Its totient is φ = 54254534400.

The previous prime is 81384732593. The next prime is 81384732613. The reversal of 81384732605 is 50623748318.

It is not a de Polignac number, because 81384732605 - 2²⁸ = 81116297149 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 81384732605.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 4029071 + ... + 4049219.

It is an arithmetic number, because the mean of its divisors is an integer number (1810598400).

Almost surely, 2^81384732605 is an apocalyptic number.

It is an amenable number.

81384732605 is a deficient number, since it is larger than the sum of its proper divisors (34493564995).

81384732605 is a wasteful number, since it uses less digits than its factorization.

81384732605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20322.

The product of its (nonzero) digits is 967680, while the sum is 47.

The spelling of 81384732605 in words is "eighty-one billion, three hundred eighty-four million, seven hundred thirty-two thousand, six hundred five".