1668516851684 has 24 divisors (see below), whose sum is σ = 2952799892280. Its totient is φ = 824860295424.

The previous prime is 1668516851669. The next prime is 1668516851707. The reversal of 1668516851684 is 4861586158661.

It can be written as a sum of positive squares in 4 ways, for example, as 143094245284 + 1525422606400 = 378278^2 + 1235080^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1668516851684.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 20555162 + ... + 20636174.

It is an arithmetic number, because the mean of its divisors is an integer number (123033328845).

Almost surely, 2^{1668516851684} is an apocalyptic number.

It is an amenable number.

1668516851684 is a deficient number, since it is larger than the sum of its proper divisors (1284283040596).

1668516851684 is a wasteful number, since it uses less digits than its factorization.

1668516851684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138959 (or 138957 counting only the distinct ones).

The product of its digits is 66355200, while the sum is 65.

The spelling of 1668516851684 in words is "one trillion, six hundred sixty-eight billion, five hundred sixteen million, eight hundred fifty-one thousand, six hundred eighty-four".