18667808639 has 4 divisors (see below), whose sum is σ = 18684983424. Its totient is φ = 18650633856.

The previous prime is 18667808623. The next prime is 18667808657. The reversal of 18667808639 is 93680876681.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 18667808639 - 2⁴ = 18667808623 is a prime.

It is a super-3 number, since 3×18667808639³ (a number of 32 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18667808609) 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, 8585762 + ... + 8587935.

It is an arithmetic number, because the mean of its divisors is an integer number (4671245856).

Almost surely, 2^18667808639 is an apocalyptic number.

18667808639 is a deficient number, since it is larger than the sum of its proper divisors (17174785).

18667808639 is a wasteful number, since it uses less digits than its factorization.

18667808639 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17174784.

The product of its (nonzero) digits is 20901888, while the sum is 62.

The spelling of 18667808639 in words is "eighteen billion, six hundred sixty-seven million, eight hundred eight thousand, six hundred thirty-nine".