165221325 has 36 divisors (see below), whose sum is σ = 297638068. Its totient is φ = 87609600.

The previous prime is 165221293. The next prime is 165221333. The reversal of 165221325 is 523122561.

It is a happy number.

165221325 is a `hidden beast` number, since 1 + 6 + 522 + 132 + 5 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 34644996 + 130576329 = 5886^2 + 11427^2 .

It is not a de Polignac number, because 165221325 - 2⁵ = 165221293 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 38697 + ... + 42753.

Almost surely, 2^165221325 is an apocalyptic number.

165221325 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

165221325 is a deficient number, since it is larger than the sum of its proper divisors (132416743).

165221325 is a wasteful number, since it uses less digits than its factorization.

165221325 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4254 (or 4246 counting only the distinct ones).

The product of its digits is 3600, while the sum is 27.

The square root of 165221325 is about 12853.8447555585. The cubic root of 165221325 is about 548.7257830095.

Adding to 165221325 its reverse (523122561), we get a palindrome (688343886).

The spelling of 165221325 in words is "one hundred sixty-five million, two hundred twenty-one thousand, three hundred twenty-five".