16660327646621 has 2 divisors, whose sum is σ = 16660327646622. Its totient is φ = 16660327646620.

The previous prime is 16660327646597. The next prime is 16660327646647. The reversal of 16660327646621 is 12664672306661.

16660327646621 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 10247713452025 + 6412614194596 = 3201205^2 + 2532314^2 .

It is a cyclic number.

It is not a de Polignac number, because 16660327646621 - 2¹⁰ = 16660327645597 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16660320646621) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8330163823310 + 8330163823311.

It is an arithmetic number, because the mean of its divisors is an integer number (8330163823311).

Almost surely, 2^{16660327646621} is an apocalyptic number.

It is an amenable number.

16660327646621 is a deficient number, since it is larger than the sum of its proper divisors (1).

16660327646621 is an equidigital number, since it uses as much as digits as its factorization.

16660327646621 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 15676416, while the sum is 56.

The spelling of 16660327646621 in words is "sixteen trillion, six hundred sixty billion, three hundred twenty-seven million, six hundred forty-six thousand, six hundred twenty-one".