18000000000081 has 24 divisors (see below), whose sum is σ = 28363778844960. Its totient is φ = 10909036108800.

The previous prime is 18000000000079. The next prime is 18000000000109.

It is a happy number.

18000000000081 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18000000000081 - 2¹ = 18000000000079 is a prime.

It is a super-2 number, since 2×18000000000081² (a number of 27 digits) contains 22 as substring.

18000000000081 is a strobogrammatic number because it is the same when read upside-down.

18000000000081 is a modest number, since divided by 81 gives 18 as remainder.

It is a junction number, because it is equal to n+sod(n) for n = 17999999999973 and 18000000000063.

It is not an unprimeable number, because it can be changed into a prime (18000000000001) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 28714641 + ... + 29334801.

It is an arithmetic number, because the mean of its divisors is an integer number (1181824118540).

Almost surely, 2^{18000000000081} is an apocalyptic number.

18000000000081 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18000000000081 is a deficient number, since it is larger than the sum of its proper divisors (10363778844879).

18000000000081 is a wasteful number, since it uses less digits than its factorization.

18000000000081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 913357 (or 913354 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

It can be divided in two parts, 180000000000 and 81, that added together give a palindrome (180000000081).

The spelling of 18000000000081 in words is "eighteen trillion, eighty-one", and thus it is an aban number and an uban number.