81168179713 has 2 divisors, whose sum is σ = 81168179714. Its totient is φ = 81168179712.

The previous prime is 81168179689. The next prime is 81168179747. The reversal of 81168179713 is 31797186118.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 54341670769 + 26826508944 = 233113^2 + 163788^2 .

It is a cyclic number.

It is not a de Polignac number, because 81168179713 - 2²¹ = 81166082561 is a prime.

It is not a weakly prime, because it can be changed into another prime (81168179773) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40584089856 + 40584089857.

It is an arithmetic number, because the mean of its divisors is an integer number (40584089857).

Almost surely, 2^81168179713 is an apocalyptic number.

It is an amenable number.

81168179713 is a deficient number, since it is larger than the sum of its proper divisors (1).

81168179713 is an equidigital number, since it uses as much as digits as its factorization.

81168179713 is an evil number, because the sum of its binary digits is even.

The product of its digits is 508032, while the sum is 52.

The spelling of 81168179713 in words is "eighty-one billion, one hundred sixty-eight million, one hundred seventy-nine thousand, seven hundred thirteen".