81013706405 has 16 divisors (see below), whose sum is σ = 98528550768. Its totient is φ = 63940800000.

The previous prime is 81013706359. The next prime is 81013706443. The reversal of 81013706405 is 50460731018.

It can be written as a sum of positive squares in 8 ways, for example, as 21204601924 + 59809104481 = 145618^2 + 244559^2 .

It is not a de Polignac number, because 81013706405 - 2²⁰ = 81012657829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 143546 + ... + 427355.

It is an arithmetic number, because the mean of its divisors is an integer number (6158034423).

Almost surely, 2^81013706405 is an apocalyptic number.

It is an amenable number.

81013706405 is a deficient number, since it is larger than the sum of its proper divisors (17514844363).

81013706405 is a wasteful number, since it uses less digits than its factorization.

81013706405 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 571288.

The product of its (nonzero) digits is 20160, while the sum is 35.

The spelling of 81013706405 in words is "eighty-one billion, thirteen million, seven hundred six thousand, four hundred five".