16561345966 has 8 divisors (see below), whose sum is σ = 27100384344. Its totient is φ = 7527884520.

The previous prime is 16561345963. The next prime is 16561345967. The reversal of 16561345966 is 66954316561.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561345963) 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, 376394205 + ... + 376394248.

It is an arithmetic number, because the mean of its divisors is an integer number (3387548043).

Almost surely, 2^16561345966 is an apocalyptic number.

16561345966 is a deficient number, since it is larger than the sum of its proper divisors (10539038378).

16561345966 is a wasteful number, since it uses less digits than its factorization.

16561345966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 752788466.

The product of its digits is 3499200, while the sum is 52.

The spelling of 16561345966 in words is "sixteen billion, five hundred sixty-one million, three hundred forty-five thousand, nine hundred sixty-six".