18838666081 has 4 divisors (see below), whose sum is σ = 18881579200. Its totient is φ = 18795752964.

The previous prime is 18838666057. The next prime is 18838666109. The reversal of 18838666081 is 18066683881.

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 18838666081 - 2⁹ = 18838665569 is a prime.

It is a super-2 number, since 2×18838666081² (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 (18838666001) 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 3 ways as a sum of consecutive naturals, for example, 21455901 + ... + 21456778.

It is an arithmetic number, because the mean of its divisors is an integer number (4720394800).

Almost surely, 2^18838666081 is an apocalyptic number.

It is an amenable number.

18838666081 is a deficient number, since it is larger than the sum of its proper divisors (42913119).

18838666081 is an equidigital number, since it uses as much as digits as its factorization.

18838666081 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42913118.

The product of its (nonzero) digits is 2654208, while the sum is 55.

The spelling of 18838666081 in words is "eighteen billion, eight hundred thirty-eight million, six hundred sixty-six thousand, eighty-one".