18666266681 has 4 divisors (see below), whose sum is σ = 18666598032. Its totient is φ = 18665935332.

The previous prime is 18666266669. The next prime is 18666266693.

18666266681 is nontrivially palindromic in base 10.

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 an interprime number because it is at equal distance from previous prime (18666266669) and next prime (18666266693).

It is a cyclic number.

It is not a de Polignac number, because 18666266681 - 2¹⁸ = 18666004537 is a prime.

It is a super-2 number, since 2×18666266681² (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 (18666266651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57731 + ... + 201656.

It is an arithmetic number, because the mean of its divisors is an integer number (4666649508).

Almost surely, 2^18666266681 is an apocalyptic number.

It is an amenable number.

18666266681 is a deficient number, since it is larger than the sum of its proper divisors (331351).

18666266681 is an equidigital number, since it uses as much as digits as its factorization.

18666266681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 331350.

The product of its digits is 5971968, while the sum is 56.

The spelling of 18666266681 in words is "eighteen billion, six hundred sixty-six million, two hundred sixty-six thousand, six hundred eighty-one".