81107013613 has 16 divisors (see below), whose sum is σ = 84869365680. Its totient is φ = 77438301696.

The previous prime is 81107013601. The next prime is 81107013751. The reversal of 81107013613 is 31631070118.

It can be written as a sum of positive squares in 8 ways, for example, as 19780453449 + 61326560164 = 140643^2 + 247642^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81107013613 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81107013313) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 455883 + ... + 608311.

It is an arithmetic number, because the mean of its divisors is an integer number (5304335355).

Almost surely, 2^81107013613 is an apocalyptic number.

It is an amenable number.

81107013613 is a deficient number, since it is larger than the sum of its proper divisors (3762352067).

81107013613 is a wasteful number, since it uses less digits than its factorization.

81107013613 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 152736.

The product of its (nonzero) digits is 3024, while the sum is 31.

The spelling of 81107013613 in words is "eighty-one billion, one hundred seven million, thirteen thousand, six hundred thirteen".