81717271718 has 8 divisors (see below), whose sum is σ = 122676136848. Its totient is φ = 40825226104.

The previous prime is 81717271697. The next prime is 81717271721.

81717271718 is nontrivially palindromic in base 10.

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

It is a super-3 number, since 3×81717271718³ (a number of 34 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16701821 + ... + 16706712.

It is an arithmetic number, because the mean of its divisors is an integer number (15334517106).

Almost surely, 2^81717271718 is an apocalyptic number.

81717271718 is a deficient number, since it is larger than the sum of its proper divisors (40958865130).

81717271718 is a wasteful number, since it uses less digits than its factorization.

81717271718 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33409758.

The product of its digits is 307328, while the sum is 50.

The spelling of 81717271718 in words is "eighty-one billion, seven hundred seventeen million, two hundred seventy-one thousand, seven hundred eighteen".