161666016065 has 16 divisors (see below), whose sum is σ = 194323708800. Its totient is φ = 129116669952.

The previous prime is 161666015933. The next prime is 161666016073. The reversal of 161666016065 is 560610666161.

It is a cyclic number.

It is not a de Polignac number, because 161666016065 - 2²⁸ = 161397580609 is a prime.

It is a super-2 number, since 2×161666016065² (a number of 23 digits) contains 22 as substring.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 7932929 + ... + 7953281.

It is an arithmetic number, because the mean of its divisors is an integer number (12145231800).

Almost surely, 2^161666016065 is an apocalyptic number.

It is an amenable number.

161666016065 is a deficient number, since it is larger than the sum of its proper divisors (32657692735).

161666016065 is a wasteful number, since it uses less digits than its factorization.

161666016065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22936.

The product of its (nonzero) digits is 233280, while the sum is 44.

The spelling of 161666016065 in words is "one hundred sixty-one billion, six hundred sixty-six million, sixteen thousand, sixty-five".