6668350386821 has 2 divisors, whose sum is σ = 6668350386822. Its totient is φ = 6668350386820.

The previous prime is 6668350386809. The next prime is 6668350386947. The reversal of 6668350386821 is 1286830538666.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3898705536196 + 2769644850625 = 1974514^2 + 1664225^2 .

It is a cyclic number.

It is not a de Polignac number, because 6668350386821 - 2¹⁰ = 6668350385797 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6668350316821) 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, 3334175193410 + 3334175193411.

It is an arithmetic number, because the mean of its divisors is an integer number (3334175193411).

Almost surely, 2^{6668350386821} is an apocalyptic number.

It is an amenable number.

6668350386821 is a deficient number, since it is larger than the sum of its proper divisors (1).

6668350386821 is an equidigital number, since it uses as much as digits as its factorization.

6668350386821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 59719680, while the sum is 62.

The spelling of 6668350386821 in words is "six trillion, six hundred sixty-eight billion, three hundred fifty million, three hundred eighty-six thousand, eight hundred twenty-one".