81795099921768 has 48 divisors (see below), whose sum is σ = 227515649564580. Its totient is φ = 26528140514304.

The previous prime is 81795099921767. The next prime is 81795099921781. The reversal of 81795099921768 is 86712999059718.

It is a happy number.

81795099921768 is a `hidden beast` number, since 8 + 1 + 7 + 9 + 509 + 9 + 92 + 17 + 6 + 8 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 73181215378404 + 8613884543364 = 8554602^2 + 2934942^2 .

It is a super-2 number, since 2×81795099921768² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (81795099921763) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 15351930505 + ... + 15351935832.

Almost surely, 2^{81795099921768} is an apocalyptic number.

It is an amenable number.

81795099921768 is an abundant number, since it is smaller than the sum of its proper divisors (145720549642812).

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

81795099921768 is a wasteful number, since it uses less digits than its factorization.

81795099921768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30703866386 (or 30703866379 counting only the distinct ones).

The product of its (nonzero) digits is 1234517760, while the sum is 81.

The spelling of 81795099921768 in words is "eighty-one trillion, seven hundred ninety-five billion, ninety-nine million, nine hundred twenty-one thousand, seven hundred sixty-eight".