18000039000021 has 64 divisors (see below), whose sum is σ = 26268830434560. Its totient is φ = 10962151200000.

The previous prime is 18000038999981. The next prime is 18000039000037. The reversal of 18000039000021 is 12000093000081.

18000039000021 is a nontrivial binomial coefficient, being equal to C(6000007, 2).

It is not a de Polignac number, because 18000039000021 - 2²⁶ = 17999971891157 is a prime.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 18000038999955 and 18000039000000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18000039000821) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1817997171 + ... + 1818007071.

It is an arithmetic number, because the mean of its divisors is an integer number (410450475540).

Almost surely, 2^{18000039000021} is an apocalyptic number.

18000039000021 is the 6000006-th triangular number.

It is an amenable number.

18000039000021 is a deficient number, since it is larger than the sum of its proper divisors (8268791434539).

18000039000021 is a wasteful number, since it uses less digits than its factorization.

18000039000021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12775 (or 12749 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 24.

The spelling of 18000039000021 in words is "eighteen trillion, thirty-nine million, twenty-one", and thus it is an aban number and an uban number.