18138439969 has 16 divisors (see below), whose sum is σ = 20819756160. Its totient is φ = 15653894400.

The previous prime is 18138439939. The next prime is 18138439973. The reversal of 18138439969 is 96993483181.

It is a cyclic number.

It is not a de Polignac number, because 18138439969 - 2¹¹ = 18138437921 is a prime.

It is a super-2 number, since 2×18138439969² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18138439919) 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, 238399 + ... + 305140.

It is an arithmetic number, because the mean of its divisors is an integer number (1301234760).

Almost surely, 2^18138439969 is an apocalyptic number.

It is an amenable number.

18138439969 is a deficient number, since it is larger than the sum of its proper divisors (2681316191).

18138439969 is a wasteful number, since it uses less digits than its factorization.

18138439969 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 543720.

The product of its digits is 10077696, while the sum is 61.

The spelling of 18138439969 in words is "eighteen billion, one hundred thirty-eight million, four hundred thirty-nine thousand, nine hundred sixty-nine".