165324321 has 12 divisors (see below), whose sum is σ = 247646672. Its totient is φ = 110216052.

The previous prime is 165324319. The next prime is 165324323. The reversal of 165324321 is 123423561.

165324321 is a `hidden beast` number, since 1 + 653 + 2 + 4 + 3 + 2 + 1 = 666.

It is an interprime number because it is at equal distance from previous prime (165324319) and next prime (165324323).

It is not a de Polignac number, because 165324321 - 2¹ = 165324319 is a prime.

It is a super-2 number, since 2×165324321² = 54664262228222082, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (165324323) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 339931 + ... + 340416.

Almost surely, 2^165324321 is an apocalyptic number.

It is an amenable number.

165324321 is a deficient number, since it is larger than the sum of its proper divisors (82322351).

165324321 is an frugal number, since it uses more digits than its factorization.

165324321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 680362 (or 680350 counting only the distinct ones).

The product of its digits is 4320, while the sum is 27.

The square root of 165324321 is about 12857.8505590942. The cubic root of 165324321 is about 548.8397812499.

Adding to 165324321 its reverse (123423561), we get a palindrome (288747882).

The spelling of 165324321 in words is "one hundred sixty-five million, three hundred twenty-four thousand, three hundred twenty-one".