1668518501869 has 2 divisors, whose sum is σ = 1668518501870. Its totient is φ = 1668518501868.

The previous prime is 1668518501857. The next prime is 1668518501891. The reversal of 1668518501869 is 9681058158661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1029741916644 + 638776585225 = 1014762^2 + 799235^2 .

It is a cyclic number.

It is not a de Polignac number, because 1668518501869 - 2⁹ = 1668518501357 is a prime.

It is a super-2 number, since 2×1668518501869² (a number of 25 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 1668518501869.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1668518901869) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 834259250934 + 834259250935.

It is an arithmetic number, because the mean of its divisors is an integer number (834259250935).

Almost surely, 2^{1668518501869} is an apocalyptic number.

It is an amenable number.

1668518501869 is a deficient number, since it is larger than the sum of its proper divisors (1).

1668518501869 is an equidigital number, since it uses as much as digits as its factorization.

1668518501869 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 24883200, while the sum is 64.

The spelling of 1668518501869 in words is "one trillion, six hundred sixty-eight billion, five hundred eighteen million, five hundred one thousand, eight hundred sixty-nine".