81729534853 has 4 divisors (see below), whose sum is σ = 82714228128. Its totient is φ = 80744841580.

The previous prime is 81729534833. The next prime is 81729534863. The reversal of 81729534853 is 35843592718.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81729534853 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 81729534794 and 81729534803.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81729534833) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 492346513 + ... + 492346678.

It is an arithmetic number, because the mean of its divisors is an integer number (20678557032).

Almost surely, 2^81729534853 is an apocalyptic number.

81729534853 is a gapful number since it is divisible by the number (83) formed by its first and last digit.

It is an amenable number.

81729534853 is a deficient number, since it is larger than the sum of its proper divisors (984693275).

81729534853 is an equidigital number, since it uses as much as digits as its factorization.

81729534853 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 984693274.

The product of its digits is 7257600, while the sum is 55.

The spelling of 81729534853 in words is "eighty-one billion, seven hundred twenty-nine million, five hundred thirty-four thousand, eight hundred fifty-three".