166643666807706 has 24 divisors (see below), whose sum is σ = 393885030636864. Its totient is φ = 50498080850760.

The previous prime is 166643666807669. The next prime is 166643666807753. The reversal of 166643666807706 is 607708666346661.

It is a happy number.

It is a super-2 number, since 2×166643666807706² (a number of 29 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 420817340226 + ... + 420817340621.

It is an arithmetic number, because the mean of its divisors is an integer number (16411876276536).

Almost surely, 2^{166643666807706} is an apocalyptic number.

166643666807706 is an abundant number, since it is smaller than the sum of its proper divisors (227241363829158).

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

166643666807706 is a wasteful number, since it uses less digits than its factorization.

166643666807706 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 841634680866 (or 841634680863 counting only the distinct ones).

The product of its (nonzero) digits is 1316818944, while the sum is 72.

The spelling of 166643666807706 in words is "one hundred sixty-six trillion, six hundred forty-three billion, six hundred sixty-six million, eight hundred seven thousand, seven hundred six".