16684538561 has 8 divisors (see below), whose sum is σ = 16819362720. Its totient is φ = 16549903648.

The previous prime is 16684538473. The next prime is 16684538567. The reversal of 16684538561 is 16583548661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16684538561 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16684538567) 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 7 ways as a sum of consecutive naturals, for example, 132470 + ... + 225648.

It is an arithmetic number, because the mean of its divisors is an integer number (2102420340).

Almost surely, 2^16684538561 is an apocalyptic number.

It is an amenable number.

16684538561 is a deficient number, since it is larger than the sum of its proper divisors (134824159).

16684538561 is a wasteful number, since it uses less digits than its factorization.

16684538561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 94623.

The product of its digits is 4147200, while the sum is 53.

The spelling of 16684538561 in words is "sixteen billion, six hundred eighty-four million, five hundred thirty-eight thousand, five hundred sixty-one".