16561560506566 has 8 divisors (see below), whose sum is σ = 24842358640800. Its totient is φ = 8280774292968.

The previous prime is 16561560506563. The next prime is 16561560506573. The reversal of 16561560506566 is 66560506516561.

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

It is a super-2 number, since 2×16561560506566² (a number of 27 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 16561560506566.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (16561560506563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2532840 + ... + 6287956.

It is an arithmetic number, because the mean of its divisors is an integer number (3105294830100).

Almost surely, 2^{16561560506566} is an apocalyptic number.

16561560506566 is a deficient number, since it is larger than the sum of its proper divisors (8280798134234).

16561560506566 is a wasteful number, since it uses less digits than its factorization.

16561560506566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5960318.

The product of its (nonzero) digits is 29160000, while the sum is 58.

The spelling of 16561560506566 in words is "sixteen trillion, five hundred sixty-one billion, five hundred sixty million, five hundred six thousand, five hundred sixty-six".