81381176959999 has 16 divisors (see below), whose sum is σ = 93057929049600. Its totient is φ = 69717146599584.

The previous prime is 81381176959969. The next prime is 81381176960021. The reversal of 81381176959999 is 99995967118318.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 81381176959999 - 2³³ = 81372587025407 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81381176959969) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 238610812 + ... + 238951630.

It is an arithmetic number, because the mean of its divisors is an integer number (5816120565600).

Almost surely, 2^{81381176959999} is an apocalyptic number.

81381176959999 is a deficient number, since it is larger than the sum of its proper divisors (11676752089601).

81381176959999 is a wasteful number, since it uses less digits than its factorization.

81381176959999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 359382.

The product of its digits is 2380855680, while the sum is 85.

The spelling of 81381176959999 in words is "eighty-one trillion, three hundred eighty-one billion, one hundred seventy-six million, nine hundred fifty-nine thousand, nine hundred ninety-nine".