16685268921 has 16 divisors (see below), whose sum is σ = 24821494720. Its totient is φ = 11077352640.

The previous prime is 16685268883. The next prime is 16685268923. The reversal of 16685268921 is 12986258661.

16685268921 is a `hidden beast` number, since 16 + 6 + 8 + 526 + 89 + 21 = 666.

It is not a de Polignac number, because 16685268921 - 2²⁹ = 16148398009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16685268923) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1275595 + ... + 1288608.

It is an arithmetic number, because the mean of its divisors is an integer number (1551343420).

Almost surely, 2^16685268921 is an apocalyptic number.

It is an amenable number.

16685268921 is a deficient number, since it is larger than the sum of its proper divisors (8136225799).

16685268921 is a wasteful number, since it uses less digits than its factorization.

16685268921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2564453 (or 2564447 counting only the distinct ones).

The product of its digits is 2488320, while the sum is 54.

The spelling of 16685268921 in words is "sixteen billion, six hundred eighty-five million, two hundred sixty-eight thousand, nine hundred twenty-one".