165638393 has 8 divisors (see below), whose sum is σ = 167060160. Its totient is φ = 164221200.

The previous prime is 165638357. The next prime is 165638411. The reversal of 165638393 is 393836561.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 165638393 - 2¹⁰ = 165637369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165638323) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129071 + ... + 130347.

It is an arithmetic number, because the mean of its divisors is an integer number (20882520).

Almost surely, 2^165638393 is an apocalyptic number.

It is an amenable number.

165638393 is a deficient number, since it is larger than the sum of its proper divisors (1421767).

165638393 is a wasteful number, since it uses less digits than its factorization.

165638393 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2287.

The product of its digits is 349920, while the sum is 44.

The square root of 165638393 is about 12870.0580029773. The cubic root of 165638393 is about 549.1871110040.

The spelling of 165638393 in words is "one hundred sixty-five million, six hundred thirty-eight thousand, three hundred ninety-three".