18866641044161 has 4 divisors (see below), whose sum is σ = 19517214873300. Its totient is φ = 18216067215024.

The previous prime is 18866641044151. The next prime is 18866641044211. The reversal of 18866641044161 is 16144014666881.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10665972174400 + 8200668869761 = 3265880^2 + 2863681^2 .

It is a cyclic number.

It is not a de Polignac number, because 18866641044161 - 2¹⁰ = 18866641043137 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 18866641044097 and 18866641044106.

It is not an unprimeable number, because it can be changed into a prime (18866641044151) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 325286914526 + ... + 325286914583.

It is an arithmetic number, because the mean of its divisors is an integer number (4879303718325).

Almost surely, 2^{18866641044161} is an apocalyptic number.

It is an amenable number.

18866641044161 is a deficient number, since it is larger than the sum of its proper divisors (650573829139).

18866641044161 is an equidigital number, since it uses as much as digits as its factorization.

18866641044161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 650573829138.

The product of its (nonzero) digits is 5308416, while the sum is 56.

The spelling of 18866641044161 in words is "eighteen trillion, eight hundred sixty-six billion, six hundred forty-one million, forty-four thousand, one hundred sixty-one".