81640362075 has 12 divisors (see below), whose sum is σ = 134978732088. Its totient is φ = 43541526400.

The previous prime is 81640362043. The next prime is 81640362113. The reversal of 81640362075 is 57026304618.

It is not a de Polignac number, because 81640362075 - 2⁵ = 81640362043 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 544269006 + ... + 544269155.

It is an arithmetic number, because the mean of its divisors is an integer number (11248227674).

Almost surely, 2^81640362075 is an apocalyptic number.

81640362075 is a deficient number, since it is larger than the sum of its proper divisors (53338370013).

81640362075 is a wasteful number, since it uses less digits than its factorization.

81640362075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1088538174 (or 1088538169 counting only the distinct ones).

The product of its (nonzero) digits is 241920, while the sum is 42.

The spelling of 81640362075 in words is "eighty-one billion, six hundred forty million, three hundred sixty-two thousand, seventy-five".