16656566636009 has 4 divisors (see below), whose sum is σ = 16726259383680. Its totient is φ = 16586873888340.

The previous prime is 16656566635999. The next prime is 16656566636033. The reversal of 16656566636009 is 90063666565661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-16656566636009 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (16656566696009) 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, 34846373477 + ... + 34846373954.

It is an arithmetic number, because the mean of its divisors is an integer number (4181564845920).

Almost surely, 2^{16656566636009} is an apocalyptic number.

It is an amenable number.

16656566636009 is a deficient number, since it is larger than the sum of its proper divisors (69692747671).

16656566636009 is an equidigital number, since it uses as much as digits as its factorization.

16656566636009 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 69692747670.

The product of its (nonzero) digits is 188956800, while the sum is 65.

The spelling of 16656566636009 in words is "sixteen trillion, six hundred fifty-six billion, five hundred sixty-six million, six hundred thirty-six thousand, nine".