165644 has 6 divisors (see below), whose sum is σ = 289884. Its totient is φ = 82820.

The previous prime is 165617. The next prime is 165653. The reversal of 165644 is 446561.

It is a happy number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20702 + ... + 20709.

It is an arithmetic number, because the mean of its divisors is an integer number (48314).

2¹⁶⁵⁶⁴⁴ is an apocalyptic number.

It is an amenable number.

165644 is a deficient number, since it is larger than the sum of its proper divisors (124240).

165644 is a wasteful number, since it uses less digits than its factorization.

165644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 41415 (or 41413 counting only the distinct ones).

The product of its digits is 2880, while the sum is 26.

The square root of 165644 is about 406.9938574475. The cubic root of 165644 is about 54.9193307750.

The spelling of 165644 in words is "one hundred sixty-five thousand, six hundred forty-four".