166023504366161 has 4 divisors (see below), whose sum is σ = 178794543163572. Its totient is φ = 153252465568752.

The previous prime is 166023504366157. The next prime is 166023504366179. The reversal of 166023504366161 is 161663405320661.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 11109262299136 + 154914242067025 = 3333056^2 + 12446455^2 .

It is a cyclic number.

It is not a de Polignac number, because 166023504366161 - 2² = 166023504366157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (166023504366191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6385519398686 + ... + 6385519398711.

It is an arithmetic number, because the mean of its divisors is an integer number (44698635790893).

Almost surely, 2^{166023504366161} is an apocalyptic number.

It is an amenable number.

166023504366161 is a deficient number, since it is larger than the sum of its proper divisors (12771038797411).

166023504366161 is a wasteful number, since it uses less digits than its factorization.

166023504366161 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12771038797410.

The product of its (nonzero) digits is 2799360, while the sum is 50.

The spelling of 166023504366161 in words is "one hundred sixty-six trillion, twenty-three billion, five hundred four million, three hundred sixty-six thousand, one hundred sixty-one".