221065 has 16 divisors (see below), whose sum is σ = 302400. Its totient is φ = 153792.

The previous prime is 221059. The next prime is 221069. The reversal of 221065 is 560122.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 221065 - 2⁹ = 220553 is a prime.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (221069) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1146 + ... + 1324.

It is an arithmetic number, because the mean of its divisors is an integer number (18900).

2²²¹⁰⁶⁵ is an apocalyptic number.

It is an amenable number.

221065 is a deficient number, since it is larger than the sum of its proper divisors (81335).

221065 is a wasteful number, since it uses less digits than its factorization.

221065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 216.

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 221065 is about 470.1754991490. The cubic root of 221065 is about 60.4653627748.

Adding to 221065 its reverse (560122), we get a palindrome (781187).

The spelling of 221065 in words is "two hundred twenty-one thousand, sixty-five".