165221573 has 4 divisors (see below), whose sum is σ = 180241728. Its totient is φ = 150201420.

The previous prime is 165221569. The next prime is 165221593. The reversal of 165221573 is 375122561.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 165221573 - 2² = 165221569 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165221533) 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 3 ways as a sum of consecutive naturals, for example, 7510061 + ... + 7510082.

It is an arithmetic number, because the mean of its divisors is an integer number (45060432).

Almost surely, 2^165221573 is an apocalyptic number.

It is an amenable number.

165221573 is a deficient number, since it is larger than the sum of its proper divisors (15020155).

165221573 is a wasteful number, since it uses less digits than its factorization.

165221573 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15020154.

The product of its digits is 12600, while the sum is 32.

The square root of 165221573 is about 12853.8544024740. The cubic root of 165221573 is about 548.7260575582.

The spelling of 165221573 in words is "one hundred sixty-five million, two hundred twenty-one thousand, five hundred seventy-three".