165638317 has 12 divisors (see below), whose sum is σ = 180278364. Its totient is φ = 151286400.

The previous prime is 165638309. The next prime is 165638323. The reversal of 165638317 is 713836561.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 7733961 + 157904356 = 2781^2 + 12566^2 .

It is not a de Polignac number, because 165638317 - 2³ = 165638309 is a prime.

It is a super-3 number, since 3×165638317³ (a number of 26 digits) contains 333 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 165638317.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165638357) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 137317 + ... + 138517.

It is an arithmetic number, because the mean of its divisors is an integer number (15023197).

Almost surely, 2^165638317 is an apocalyptic number.

It is an amenable number.

165638317 is a deficient number, since it is larger than the sum of its proper divisors (14640047).

165638317 is a wasteful number, since it uses less digits than its factorization.

165638317 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1420 (or 1317 counting only the distinct ones).

The product of its digits is 90720, while the sum is 40.

The square root of 165638317 is about 12870.0550503873. The cubic root of 165638317 is about 549.1870270093.

The spelling of 165638317 in words is "one hundred sixty-five million, six hundred thirty-eight thousand, three hundred seventeen".