166606566651 has 24 divisors (see below), whose sum is σ = 279541807584. Its totient is φ = 93643032960.

The previous prime is 166606566619. The next prime is 166606566653. The reversal of 166606566651 is 156665606661.

It is not a de Polignac number, because 166606566651 - 2⁵ = 166606566619 is a prime.

It is not an unprimeable number, because it can be changed into a prime (166606566653) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 21672786 + ... + 21680471.

It is an arithmetic number, because the mean of its divisors is an integer number (11647575316).

Almost surely, 2^166606566651 is an apocalyptic number.

166606566651 is a deficient number, since it is larger than the sum of its proper divisors (112935240933).

166606566651 is a wasteful number, since it uses less digits than its factorization.

166606566651 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 43353331 (or 43353328 counting only the distinct ones).

The product of its (nonzero) digits is 6998400, while the sum is 54.

The spelling of 166606566651 in words is "one hundred sixty-six billion, six hundred six million, five hundred sixty-six thousand, six hundred fifty-one".