2666663392021 has 2 divisors, whose sum is σ = 2666663392022. Its totient is φ = 2666663392020.

The previous prime is 2666663391901. The next prime is 2666663392037. The reversal of 2666663392021 is 1202933666662.

2666663392021 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1956501562500 + 710161829521 = 1398750^2 + 842711^2 .

It is a cyclic number.

It is not a de Polignac number, because 2666663392021 - 2³⁵ = 2632303653653 is a prime.

It is a super-2 number, since 2×2666663392021² (a number of 26 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 2666663392021.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2666663392121) 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 as a sum of consecutive naturals, namely, 1333331696010 + 1333331696011.

It is an arithmetic number, because the mean of its divisors is an integer number (1333331696011).

Almost surely, 2^{2666663392021} is an apocalyptic number.

It is an amenable number.

2666663392021 is a deficient number, since it is larger than the sum of its proper divisors (1).

2666663392021 is an equidigital number, since it uses as much as digits as its factorization.

2666663392021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5038848, while the sum is 52.

The spelling of 2666663392021 in words is "two trillion, six hundred sixty-six billion, six hundred sixty-three million, three hundred ninety-two thousand, twenty-one".