166680181656 has 192 divisors, whose sum is σ = 483269885280. Its totient is φ = 51716321280.

The previous prime is 166680181609. The next prime is 166680181697. The reversal of 166680181656 is 656181086661.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 43620226 + ... + 43624046.

Almost surely, 2^166680181656 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 166680181656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (241634942640).

166680181656 is an abundant number, since it is smaller than the sum of its proper divisors (316589703624).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

166680181656 is a wasteful number, since it uses less digits than its factorization.

166680181656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4234 (or 4227 counting only the distinct ones).

The product of its (nonzero) digits is 2488320, while the sum is 54.

The spelling of 166680181656 in words is "one hundred sixty-six billion, six hundred eighty million, one hundred eighty-one thousand, six hundred fifty-six".