81597707813 has 8 divisors (see below), whose sum is σ = 84248338176. Its totient is φ = 78948230400.

The previous prime is 81597707803. The next prime is 81597707837. The reversal of 81597707813 is 31870779518.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 81597707813 - 2¹⁸ = 81597445669 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81597707803) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 143228 + ... + 428613.

It is an arithmetic number, because the mean of its divisors is an integer number (10531042272).

Almost surely, 2^81597707813 is an apocalyptic number.

It is an amenable number.

81597707813 is a deficient number, since it is larger than the sum of its proper divisors (2650630363).

81597707813 is a wasteful number, since it uses less digits than its factorization.

81597707813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 576475.

The product of its (nonzero) digits is 2963520, while the sum is 56.

The spelling of 81597707813 in words is "eighty-one billion, five hundred ninety-seven million, seven hundred seven thousand, eight hundred thirteen".