Adding to 165221325 its reverse (523122561), we get a palindrome (688343886).
It is a happy number.
165221325 is a `hidden beast` number, since 1 + 6 + 522 + 132 + 5 = 666.
It is a Duffinian number.
It is a congruent number.
It is an unprimeable number.
Almost surely, 2165221325 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 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 square root of 165221325 is about 12853.8447555585. The cubic root of 165221325 is about 548.7257830095.
The spelling of 165221325 in words is "one hundred sixty-five million, two hundred twenty-one thousand, three hundred twenty-five".