16655566643 has 4 divisors (see below), whose sum is σ = 16656564120. Its totient is φ = 16654569168.

The previous prime is 16655566639. The next prime is 16655566651. The reversal of 16655566643 is 34666555661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 16655566643 - 2² = 16655566639 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16655566663) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 473258 + ... + 507231.

It is an arithmetic number, because the mean of its divisors is an integer number (4164141030).

Almost surely, 2^16655566643 is an apocalyptic number.

16655566643 is a deficient number, since it is larger than the sum of its proper divisors (997477).

16655566643 is an equidigital number, since it uses as much as digits as its factorization.

16655566643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 997476.

The product of its digits is 11664000, while the sum is 53.

The spelling of 16655566643 in words is "sixteen billion, six hundred fifty-five million, five hundred sixty-six thousand, six hundred forty-three".