16645678313209 has 8 divisors (see below), whose sum is σ = 18377703987552. Its totient is φ = 14950116337440.

The previous prime is 16645678313207. The next prime is 16645678313227. The reversal of 16645678313209 is 90231387654661.

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 not a de Polignac number, because 16645678313209 - 2¹ = 16645678313207 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16645678313207) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 9115923684 + ... + 9115925509.

It is an arithmetic number, because the mean of its divisors is an integer number (2297212998444).

It is a 1-persistent number, because it is pandigital, but 2⋅16645678313209 = 33291356626418 is not.

Almost surely, 2^{16645678313209} is an apocalyptic number.

It is an amenable number.

16645678313209 is a deficient number, since it is larger than the sum of its proper divisors (1732025674343).

16645678313209 is a wasteful number, since it uses less digits than its factorization.

16645678313209 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18231849287.

The product of its (nonzero) digits is 39191040, while the sum is 61.

The spelling of 16645678313209 in words is "sixteen trillion, six hundred forty-five billion, six hundred seventy-eight million, three hundred thirteen thousand, two hundred nine".