81864949867239 has 64 divisors (see below), whose sum is σ = 136175929344000. Its totient is φ = 42499525201920.

The previous prime is 81864949867159. The next prime is 81864949867303. The reversal of 81864949867239 is 93276894946818.

It is not a de Polignac number, because 81864949867239 - 2⁸ = 81864949866983 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81864949867139) by changing a digit.

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, 2394885342 + ... + 2394919524.

It is an arithmetic number, because the mean of its divisors is an integer number (2127748896000).

Almost surely, 2^{81864949867239} is an apocalyptic number.

81864949867239 is a deficient number, since it is larger than the sum of its proper divisors (54310979476761).

81864949867239 is a wasteful number, since it uses less digits than its factorization.

81864949867239 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 40660.

The product of its digits is 9029615616, while the sum is 84.

The spelling of 81864949867239 in words is "eighty-one trillion, eight hundred sixty-four billion, nine hundred forty-nine million, eight hundred sixty-seven thousand, two hundred thirty-nine".