81717071718 has 32 divisors (see below), whose sum is σ = 165760968672. Its totient is φ = 26853536000.

The previous prime is 81717071651. The next prime is 81717071719.

81717071718 is nontrivially palindromic in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81717071719) 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, 148173 + ... + 430568.

It is an arithmetic number, because the mean of its divisors is an integer number (5180030271).

Almost surely, 2^81717071718 is an apocalyptic number.

81717071718 is an abundant number, since it is smaller than the sum of its proper divisors (84043896954).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81717071718 is a wasteful number, since it uses less digits than its factorization.

81717071718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 579080.

The product of its (nonzero) digits is 153664, while the sum is 48.

It can be divided in two parts, 817170 and 71718, that added together give a palindrome (888888).

The spelling of 81717071718 in words is "eighty-one billion, seven hundred seventeen million, seventy-one thousand, seven hundred eighteen".