81959016843 has 48 divisors (see below), whose sum is σ = 136150290432. Its totient is φ = 47046960000.

The previous prime is 81959016793. The next prime is 81959016869. The reversal of 81959016843 is 34861095918.

81959016843 is a `hidden beast` number, since 8 + 1 + 9 + 590 + 1 + 6 + 8 + 43 = 666.

It is not a de Polignac number, because 81959016843 - 2⁹ = 81959016331 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 81959016843.

It is not an unprimeable number, because it can be changed into a prime (81959017843) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 139858 + ... + 428343.

It is an arithmetic number, because the mean of its divisors is an integer number (2836464384).

Almost surely, 2^81959016843 is an apocalyptic number.

81959016843 is a deficient number, since it is larger than the sum of its proper divisors (54191273589).

81959016843 is a wasteful number, since it uses less digits than its factorization.

81959016843 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 568296 (or 568293 counting only the distinct ones).

The product of its (nonzero) digits is 1866240, while the sum is 54.

The spelling of 81959016843 in words is "eighty-one billion, nine hundred fifty-nine million, sixteen thousand, eight hundred forty-three".