18664611646681 has 48 divisors (see below), whose sum is σ = 25522416456768. Its totient is φ = 13417339824000.

The previous prime is 18664611646679. The next prime is 18664611646693.

18664611646681 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 18664611646681 - 2¹ = 18664611646679 is a prime.

It is a super-2 number, since 2×18664611646681² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (18664611646661) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 11374606 + ... + 12911656.

It is an arithmetic number, because the mean of its divisors is an integer number (531717009516).

Almost surely, 2^{18664611646681} is an apocalyptic number.

18664611646681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

18664611646681 is a deficient number, since it is larger than the sum of its proper divisors (6857804810087).

18664611646681 is a wasteful number, since it uses less digits than its factorization.

18664611646681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1538822 (or 1538815 counting only the distinct ones).

The product of its digits is 47775744, while the sum is 64.

The spelling of 18664611646681 in words is "eighteen trillion, six hundred sixty-four billion, six hundred eleven million, six hundred forty-six thousand, six hundred eighty-one".