18000009000001 has 24 divisors (see below), whose sum is σ = 20969465029800. Its totient is φ = 15405984179712.

The previous prime is 18000008999911. The next prime is 18000009000031. The reversal of 18000009000001 is 10000090000081.

18000009000001 is a nontrivial binomial coefficient, being equal to C(6000002, 2).

It can be written as a sum of positive squares in 4 ways, for example, as 205321359376 + 17794687640625 = 453124^2 + 4218375^2 .

It is not a de Polignac number, because 18000009000001 - 2¹¹ = 18000008997953 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18000009000031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 146938825 + ... + 147061273.

It is an arithmetic number, because the mean of its divisors is an integer number (873727709575).

Almost surely, 2^{18000009000001} is an apocalyptic number.

18000009000001 is the 6000001-st triangular number and also the 3000001-st hexagonal number.

18000009000001 is the 2000001-st centered nonagonal number.

It is an amenable number.

18000009000001 is a deficient number, since it is larger than the sum of its proper divisors (2969456029799).

18000009000001 is a wasteful number, since it uses less digits than its factorization.

18000009000001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 126833 (or 126826 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 19.

Adding to 18000009000001 its reverse (10000090000081), we get a palindrome (28000099000082).

The spelling of 18000009000001 in words is "eighteen trillion, nine million, one", and thus it is an aban number and an uban number.