165638044 has 24 divisors (see below), whose sum is σ = 340543728. Its totient is φ = 69498240.

The previous prime is 165638017. The next prime is 165638051. The reversal of 165638044 is 440836561.

It is a happy number.

It is a super-3 number, since 3×165638044³ (a number of 26 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 165637994 and 165638012.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 144217 + ... + 145360.

It is an arithmetic number, because the mean of its divisors is an integer number (14189322).

Almost surely, 2^165638044 is an apocalyptic number.

It is an amenable number.

165638044 is an abundant number, since it is smaller than the sum of its proper divisors (174905684).

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

165638044 is a wasteful number, since it uses less digits than its factorization.

165638044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 289605 (or 289603 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 37.

The square root of 165638044 is about 12870.0444443677. The cubic root of 165638044 is about 549.1867252914.

The spelling of 165638044 in words is "one hundred sixty-five million, six hundred thirty-eight thousand, forty-four".