16684176683921 has 2 divisors, whose sum is σ = 16684176683922. Its totient is φ = 16684176683920.

The previous prime is 16684176683893. The next prime is 16684176684017. The reversal of 16684176683921 is 12938667148661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 16654683430225 + 29493253696 = 4081015^2 + 171736^2 .

It is an emirp because it is prime and its reverse (12938667148661) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16684176683921 is a prime.

It is not a weakly prime, because it can be changed into another prime (16684176683021) by changing a digit.

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 as a sum of consecutive naturals, namely, 8342088341960 + 8342088341961.

It is an arithmetic number, because the mean of its divisors is an integer number (8342088341961).

Almost surely, 2^{16684176683921} is an apocalyptic number.

It is an amenable number.

16684176683921 is a deficient number, since it is larger than the sum of its proper divisors (1).

16684176683921 is an equidigital number, since it uses as much as digits as its factorization.

16684176683921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 125411328, while the sum is 68.

The spelling of 16684176683921 in words is "sixteen trillion, six hundred eighty-four billion, one hundred seventy-six million, six hundred eighty-three thousand, nine hundred twenty-one".