221265 has 32 divisors (see below), whose sum is σ = 432000. Its totient is φ = 106560.

The previous prime is 221261. The next prime is 221281. The reversal of 221265 is 562122.

It is not a de Polignac number, because 221265 - 2² = 221261 is a prime.

It is an Ulam number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (221261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1411 + ... + 1559.

It is an arithmetic number, because the mean of its divisors is an integer number (13500).

2²²¹²⁶⁵ is an apocalyptic number.

It is an amenable number.

221265 is a deficient number, since it is larger than the sum of its proper divisors (210735).

221265 is a wasteful number, since it uses less digits than its factorization.

221265 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174 (or 168 counting only the distinct ones).

The product of its digits is 240, while the sum is 18.

The square root of 221265 is about 470.3881376055. The cubic root of 221265 is about 60.4835918439.

Adding to 221265 its reverse (562122), we get a palindrome (783387).

The spelling of 221265 in words is "two hundred twenty-one thousand, two hundred sixty-five".