166656566649 has 16 divisors (see below), whose sum is σ = 231406677504. Its totient is φ = 106568851200.

The previous prime is 166656566639. The next prime is 166656566653. The reversal of 166656566649 is 946665656661.

166656566649 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 166656566649 - 2¹¹ = 166656564601 is a prime.

It is a super-2 number, since 2×166656566649² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 166656566649.

It is not an unprimeable number, because it can be changed into a prime (166656566639) 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 15 ways as a sum of consecutive naturals, for example, 7918722 + ... + 7939739.

It is an arithmetic number, because the mean of its divisors is an integer number (14462917344).

Almost surely, 2^166656566649 is an apocalyptic number.

It is an amenable number.

166656566649 is a deficient number, since it is larger than the sum of its proper divisors (64750110855).

166656566649 is a wasteful number, since it uses less digits than its factorization.

166656566649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15858608.

The product of its digits is 251942400, while the sum is 66.

The spelling of 166656566649 in words is "one hundred sixty-six billion, six hundred fifty-six million, five hundred sixty-six thousand, six hundred forty-nine".