81316860768 has 192 divisors, whose sum is σ = 278638617600. Its totient is φ = 22745940480.

The previous prime is 81316860739. The next prime is 81316860773. The reversal of 81316860768 is 86706861318.

81316860768 is a `hidden beast` number, since 8 + 13 + 16 + 8 + 607 + 6 + 8 = 666.

It is a super-2 number, since 2×81316860768² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 205528 + ... + 452631.

It is an arithmetic number, because the mean of its divisors is an integer number (1451242800).

Almost surely, 2^81316860768 is an apocalyptic number.

81316860768 is a gapful number since it is divisible by the number (88) formed by its first and last digit.

It is an amenable number.

81316860768 is an abundant number, since it is smaller than the sum of its proper divisors (197321756832).

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

81316860768 is a wasteful number, since it uses less digits than its factorization.

81316860768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 658202 (or 658188 counting only the distinct ones).

The product of its (nonzero) digits is 2322432, while the sum is 54.

The spelling of 81316860768 in words is "eighty-one billion, three hundred sixteen million, eight hundred sixty thousand, seven hundred sixty-eight".