1668686703617 has 2 divisors, whose sum is σ = 1668686703618. Its totient is φ = 1668686703616.

The previous prime is 1668686703611. The next prime is 1668686703637. The reversal of 1668686703617 is 7163076868661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1665999421696 + 2687281921 = 1290736^2 + 51839^2 .

It is a cyclic number.

It is not a de Polignac number, because 1668686703617 - 2⁸ = 1668686703361 is a prime.

It is not a weakly prime, because it can be changed into another prime (1668686703611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834343351808 + 834343351809.

It is an arithmetic number, because the mean of its divisors is an integer number (834343351809).

Almost surely, 2^{1668686703617} is an apocalyptic number.

It is an amenable number.

1668686703617 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668686703617 is an equidigital number, since it uses as much as digits as its factorization.

1668686703617 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 73156608, while the sum is 65.

The spelling of 1668686703617 in words is "one trillion, six hundred sixty-eight billion, six hundred eighty-six million, seven hundred three thousand, six hundred seventeen".