16669643345 has 4 divisors (see below), whose sum is σ = 20003572020. Its totient is φ = 13335714672.

The previous prime is 16669643303. The next prime is 16669643351. The reversal of 16669643345 is 54334696661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54334696661 = 7 ⋅7762099523.

It can be written as a sum of positive squares in 2 ways, for example, as 7779416401 + 8890226944 = 88201^2 + 94288^2 .

It is a cyclic number.

It is not a de Polignac number, because 16669643345 - 2¹² = 16669639249 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1666964330 + ... + 1666964339.

It is an arithmetic number, because the mean of its divisors is an integer number (5000893005).

Almost surely, 2^16669643345 is an apocalyptic number.

It is an amenable number.

16669643345 is a deficient number, since it is larger than the sum of its proper divisors (3333928675).

16669643345 is an equidigital number, since it uses as much as digits as its factorization.

16669643345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3333928674.

The product of its digits is 8398080, while the sum is 53.

The spelling of 16669643345 in words is "sixteen billion, six hundred sixty-nine million, six hundred forty-three thousand, three hundred forty-five".