81317823771016 has 16 divisors (see below), whose sum is σ = 174252479509440. Its totient is φ = 34850495901840.

The previous prime is 81317823770987. The next prime is 81317823771071. The reversal of 81317823771016 is 61017732871318.

It is a super-2 number, since 2×81317823771016² (a number of 29 digits) contains 22 as substring.

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, 726051997900 + ... + 726051998011.

It is an arithmetic number, because the mean of its divisors is an integer number (10890779969340).

Almost surely, 2^{81317823771016} is an apocalyptic number.

It is an amenable number.

81317823771016 is an abundant number, since it is smaller than the sum of its proper divisors (92934655738424).

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

81317823771016 is a wasteful number, since it uses less digits than its factorization.

81317823771016 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1452103995924 (or 1452103995920 counting only the distinct ones).

The product of its (nonzero) digits is 2370816, while the sum is 55.

The spelling of 81317823771016 in words is "eighty-one trillion, three hundred seventeen billion, eight hundred twenty-three million, seven hundred seventy-one thousand, sixteen".