16686838646789 has 2 divisors, whose sum is σ = 16686838646790. Its totient is φ = 16686838646788.

The previous prime is 16686838646741. The next prime is 16686838646851. The reversal of 16686838646789 is 98764683868661.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13493558996164 + 3193279650625 = 3673358^2 + 1786975^2 .

It is a cyclic number.

It is not a de Polignac number, because 16686838646789 - 2³⁶ = 16618119170053 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 16686838646789.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16686838646719) 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 as a sum of consecutive naturals, namely, 8343419323394 + 8343419323395.

It is an arithmetic number, because the mean of its divisors is an integer number (8343419323395).

Almost surely, 2^{16686838646789} is an apocalyptic number.

It is an amenable number.

16686838646789 is a deficient number, since it is larger than the sum of its proper divisors (1).

16686838646789 is an equidigital number, since it uses as much as digits as its factorization.

16686838646789 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 24078974976, while the sum is 86.

The spelling of 16686838646789 in words is "sixteen trillion, six hundred eighty-six billion, eight hundred thirty-eight million, six hundred forty-six thousand, seven hundred eighty-nine".