81743831513 has 16 divisors (see below), whose sum is σ = 86532572160. Its totient is φ = 77063610624.

The previous prime is 81743831483. The next prime is 81743831551. The reversal of 81743831513 is 31513834718.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81743831513 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81743831563) 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, 576920 + ... + 704502.

It is an arithmetic number, because the mean of its divisors is an integer number (5408285760).

Almost surely, 2^81743831513 is an apocalyptic number.

It is an amenable number.

81743831513 is a deficient number, since it is larger than the sum of its proper divisors (4788740647).

81743831513 is a wasteful number, since it uses less digits than its factorization.

81743831513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 128008.

The product of its digits is 241920, while the sum is 44.

The spelling of 81743831513 in words is "eighty-one billion, seven hundred forty-three million, eight hundred thirty-one thousand, five hundred thirteen".