165573221 has 16 divisors (see below), whose sum is σ = 183351168. Its totient is φ = 148267200.

The previous prime is 165573203. The next prime is 165573241. The reversal of 165573221 is 122375561.

It is a cyclic number.

It is not a de Polignac number, because 165573221 - 2⁶ = 165573157 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (165573241) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 358931 + ... + 359391.

It is an arithmetic number, because the mean of its divisors is an integer number (11459448).

Almost surely, 2^165573221 is an apocalyptic number.

165573221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

165573221 is a deficient number, since it is larger than the sum of its proper divisors (17777947).

165573221 is a wasteful number, since it uses less digits than its factorization.

165573221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 892.

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

The square root of 165573221 is about 12867.5258305550. The cubic root of 165573221 is about 549.1150739258.

The spelling of 165573221 in words is "one hundred sixty-five million, five hundred seventy-three thousand, two hundred twenty-one".