166193910021 has 8 divisors (see below), whose sum is σ = 223743257920. Its totient is φ = 109720251072.

The previous prime is 166193910019. The next prime is 166193910031. The reversal of 166193910021 is 120019391661.

166193910021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 166193910021 - 2¹ = 166193910019 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166193910031) 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 7 ways as a sum of consecutive naturals, for example, 268921876 + ... + 268922493.

It is an arithmetic number, because the mean of its divisors is an integer number (27967907240).

Almost surely, 2^166193910021 is an apocalyptic number.

It is an amenable number.

166193910021 is a deficient number, since it is larger than the sum of its proper divisors (57549347899).

166193910021 is a wasteful number, since it uses less digits than its factorization.

166193910021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 537844475.

The product of its (nonzero) digits is 17496, while the sum is 39.

The spelling of 166193910021 in words is "one hundred sixty-six billion, one hundred ninety-three million, nine hundred ten thousand, twenty-one".