165159666 has 72 divisors (see below), whose sum is σ = 431743104. Its totient is φ = 44692560.

The previous prime is 165159613. The next prime is 165159671. The reversal of 165159666 is 666951561.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 43671 + ... + 47301.

It is an arithmetic number, because the mean of its divisors is an integer number (5996432).

Almost surely, 2^165159666 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 165159666, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (215871552).

165159666 is an abundant number, since it is smaller than the sum of its proper divisors (266583438).

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

165159666 is a wasteful number, since it uses less digits than its factorization.

165159666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3684 (or 3662 counting only the distinct ones).

The product of its digits is 291600, while the sum is 45.

The square root of 165159666 is about 12851.4460664938. The cubic root of 165159666 is about 548.6575147986.

The spelling of 165159666 in words is "one hundred sixty-five million, one hundred fifty-nine thousand, six hundred sixty-six".