16686838646784 has 336 divisors, whose sum is σ = 50241158358300. Its totient is φ = 5538291646464.

The previous prime is 16686838646741. The next prime is 16686838646789. The reversal of 16686838646784 is 48764683868661.

16686838646784 is a `hidden beast` number, since 1 + 6 + 68 + 68 + 38 + 6 + 467 + 8 + 4 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 16680101520384 + 6737126400 = 4084128^2 + 82080^2 .

It is a Harshad number since it is a multiple of its sum of digits (81).

It is not an unprimeable number, because it can be changed into a prime (16686838646789) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 347843152 + ... + 347891120.

Almost surely, 2^{16686838646784} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 16686838646784, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25120579179150).

16686838646784 is an abundant number, since it is smaller than the sum of its proper divisors (33554319711516).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

16686838646784 is an frugal number, since it uses more digits than its factorization.

16686838646784 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48242 (or 48207 counting only the distinct ones).

The product of its digits is 10701766656, while the sum is 81.

The spelling of 16686838646784 in words is "sixteen trillion, six hundred eighty-six billion, eight hundred thirty-eight million, six hundred forty-six thousand, seven hundred eighty-four".