81610864231 has 16 divisors (see below), whose sum is σ = 89606847456. Its totient is φ = 73862246016.

The previous prime is 81610864219. The next prime is 81610864261. The reversal of 81610864231 is 13246801618.

It is not a de Polignac number, because 81610864231 - 2¹¹ = 81610862183 is a prime.

It is a super-2 number, since 2×81610864231² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81610864201) 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 15 ways as a sum of consecutive naturals, for example, 1010461 + ... + 1088233.

It is an arithmetic number, because the mean of its divisors is an integer number (5600427966).

Almost surely, 2^81610864231 is an apocalyptic number.

81610864231 is a deficient number, since it is larger than the sum of its proper divisors (7995983225).

81610864231 is a wasteful number, since it uses less digits than its factorization.

81610864231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79362.

The product of its (nonzero) digits is 55296, while the sum is 40.

The spelling of 81610864231 in words is "eighty-one billion, six hundred ten million, eight hundred sixty-four thousand, two hundred thirty-one".