16685666129 has 4 divisors (see below), whose sum is σ = 18202544880. Its totient is φ = 15168787380.

The previous prime is 16685666119. The next prime is 16685666149. The reversal of 16685666129 is 92166658661.

It is a happy number.

16685666129 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 16685666129 - 2¹⁶ = 16685600593 is a prime.

It is a super-2 number, since 2×16685666129² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16685666119) 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 3 ways as a sum of consecutive naturals, for example, 758439359 + ... + 758439380.

It is an arithmetic number, because the mean of its divisors is an integer number (4550636220).

Almost surely, 2^16685666129 is an apocalyptic number.

It is an amenable number.

16685666129 is a deficient number, since it is larger than the sum of its proper divisors (1516878751).

16685666129 is a wasteful number, since it uses less digits than its factorization.

16685666129 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1516878750.

The product of its digits is 5598720, while the sum is 56.

The spelling of 16685666129 in words is "sixteen billion, six hundred eighty-five million, six hundred sixty-six thousand, one hundred twenty-nine".