1668085513 has 2 divisors, whose sum is σ = 1668085514. Its totient is φ = 1668085512.

The previous prime is 1668085501. The next prime is 1668085519. The reversal of 1668085513 is 3155808661.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1666925584 + 1159929 = 40828^2 + 1077^2 .

It is an emirp because it is prime and its reverse (3155808661) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1668085513 - 2¹⁷ = 1667954441 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1668085513.

It is not a weakly prime, because it can be changed into another prime (1668085519) 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 as a sum of consecutive naturals, namely, 834042756 + 834042757.

It is an arithmetic number, because the mean of its divisors is an integer number (834042757).

Almost surely, 2^1668085513 is an apocalyptic number.

It is an amenable number.

1668085513 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668085513 is an equidigital number, since it uses as much as digits as its factorization.

1668085513 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 172800, while the sum is 43.

The square root of 1668085513 is about 40842.2025973135. The cubic root of 1668085513 is about 1185.9674517371.

The spelling of 1668085513 in words is "one billion, six hundred sixty-eight million, eighty-five thousand, five hundred thirteen".