166665722165 has 16 divisors (see below), whose sum is σ = 206276509440. Its totient is φ = 129203659200.

The previous prime is 166665722131. The next prime is 166665722177. The reversal of 166665722165 is 561227566661.

It is not a de Polignac number, because 166665722165 - 2¹² = 166665718069 is a prime.

It is a Curzon number.

It is a congruent 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, 3487235 + ... + 3534704.

It is an arithmetic number, because the mean of its divisors is an integer number (12892281840).

Almost surely, 2^166665722165 is an apocalyptic number.

It is an amenable number.

166665722165 is a deficient number, since it is larger than the sum of its proper divisors (39610787275).

166665722165 is a wasteful number, since it uses less digits than its factorization.

166665722165 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7022092.

The product of its digits is 5443200, while the sum is 53.

The spelling of 166665722165 in words is "one hundred sixty-six billion, six hundred sixty-five million, seven hundred twenty-two thousand, one hundred sixty-five".