1668518686849 has 4 divisors (see below), whose sum is σ = 1906878499264. Its totient is φ = 1430158874436.

The previous prime is 1668518686843. The next prime is 1668518686903. The reversal of 1668518686849 is 9486868158661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1668518686849 - 2⁹ = 1668518686337 is a prime.

It is a super-2 number, since 2×1668518686849² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1668518686843) 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 in 3 ways as a sum of consecutive naturals, for example, 119179906197 + ... + 119179906210.

It is an arithmetic number, because the mean of its divisors is an integer number (476719624816).

Almost surely, 2^{1668518686849} is an apocalyptic number.

It is an amenable number.

1668518686849 is a deficient number, since it is larger than the sum of its proper divisors (238359812415).

1668518686849 is an equidigital number, since it uses as much as digits as its factorization.

1668518686849 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 238359812414.

The product of its digits is 955514880, while the sum is 76.

The spelling of 1668518686849 in words is "one trillion, six hundred sixty-eight billion, five hundred eighteen million, six hundred eighty-six thousand, eight hundred forty-nine".