165666123 has 12 divisors (see below), whose sum is σ = 273480688. Its totient is φ = 94666320.

The previous prime is 165666121. The next prime is 165666133. The reversal of 165666123 is 321666561.

It is not a de Polignac number, because 165666123 - 2¹ = 165666121 is a prime.

It is a super-2 number, since 2×165666123² = 54890528619702258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165666121) 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 11 ways as a sum of consecutive naturals, for example, 1314748 + ... + 1314873.

Almost surely, 2^165666123 is an apocalyptic number.

165666123 is a deficient number, since it is larger than the sum of its proper divisors (107814565).

165666123 is a wasteful number, since it uses less digits than its factorization.

165666123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2629634 (or 2629631 counting only the distinct ones).

The product of its digits is 38880, while the sum is 36.

The square root of 165666123 is about 12871.1352646144. The cubic root of 165666123 is about 549.2177562921.

The spelling of 165666123 in words is "one hundred sixty-five million, six hundred sixty-six thousand, one hundred twenty-three".