81165756530 has 32 divisors (see below), whose sum is σ = 149297679360. Its totient is φ = 31756184640.

The previous prime is 81165756527. The next prime is 81165756533. The reversal of 81165756530 is 3565756118.

It is an interprime number because it is at equal distance from previous prime (81165756527) and next prime (81165756533).

It is a Harshad number since it is a multiple of its sum of digits (47).

It is not an unprimeable number, because it can be changed into a prime (81165756533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 732695 + ... + 836165.

It is an arithmetic number, because the mean of its divisors is an integer number (4665552480).

Almost surely, 2^81165756530 is an apocalyptic number.

81165756530 is a deficient number, since it is larger than the sum of its proper divisors (68131922830).

81165756530 is a wasteful number, since it uses less digits than its factorization.

81165756530 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 105194.

The product of its (nonzero) digits is 756000, while the sum is 47.

The spelling of 81165756530 in words is "eighty-one billion, one hundred sixty-five million, seven hundred fifty-six thousand, five hundred thirty".