18000011000081 has 4 divisors (see below), whose sum is σ = 19636375636464. Its totient is φ = 16363646363700.

The previous prime is 18000011000071. The next prime is 18000011000087.

18000011000081 is nontrivially palindromic in base 10.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 18000011000081 - 2³⁸ = 17725133093137 is a prime.

It is a super-2 number, since 2×18000011000081² (a number of 27 digits) contains 22 as substring.

18000011000081 is a strobogrammatic number because it is the same when read upside-down.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18000011000087) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 818182318175 + ... + 818182318196.

It is an arithmetic number, because the mean of its divisors is an integer number (4909093909116).

Almost surely, 2^{18000011000081} is an apocalyptic number.

18000011000081 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18000011000081 is a deficient number, since it is larger than the sum of its proper divisors (1636364636383).

18000011000081 is a wasteful number, since it uses less digits than its factorization.

18000011000081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1636364636382.

The product of its (nonzero) digits is 64, while the sum is 20.

It can be divided in two parts, 1800001 and 1000081, that added together give a palindrome (2800082).

The spelling of 18000011000081 in words is "eighteen trillion, eleven million, eighty-one", and thus it is an aban number and an uban number.