165621328 has 20 divisors (see below), whose sum is σ = 337780960. Its totient is φ = 78452064.

The previous prime is 165621317. The next prime is 165621329. The reversal of 165621328 is 823126561.

It is a junction number, because it is equal to n+sod(n) for n = 165621293 and 165621302.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165621329) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 272100 + ... + 272707.

It is an arithmetic number, because the mean of its divisors is an integer number (16889048).

Almost surely, 2^165621328 is an apocalyptic number.

It is an amenable number.

165621328 is an abundant number, since it is smaller than the sum of its proper divisors (172159632).

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

165621328 is a wasteful number, since it uses less digits than its factorization.

165621328 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 544834 (or 544828 counting only the distinct ones).

The product of its digits is 17280, while the sum is 34.

The square root of 165621328 is about 12869.3950129756. The cubic root of 165621328 is about 549.1682502400.

Adding to 165621328 its reverse (823126561), we get a palindrome (988747889).

The spelling of 165621328 in words is "one hundred sixty-five million, six hundred twenty-one thousand, three hundred twenty-eight".