365221 has 4 divisors (see below), whose sum is σ = 366444. Its totient is φ = 364000.

The previous prime is 365213. The next prime is 365231. The reversal of 365221 is 122563.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 122563 = 7 ⋅17509.

It can be written as a sum of positive squares in 2 ways, for example, as 216225 + 148996 = 465^2 + 386^2 .

It is a cyclic number.

It is not a de Polignac number, because 365221 - 2³ = 365213 is a prime.

It is a d-powerful number, because it can be written as 3³ + 6⁷ + 2¹² + 5⁶ + 2¹⁶ + 1 .

It is a Duffinian number.

It is a nialpdrome in base 15.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (365201) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 171 + ... + 871.

It is an arithmetic number, because the mean of its divisors is an integer number (91611).

2³⁶⁵²²¹ is an apocalyptic number.

It is an amenable number.

365221 is a deficient number, since it is larger than the sum of its proper divisors (1223).

365221 is an equidigital number, since it uses as much as digits as its factorization.

365221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1222.

The product of its digits is 360, while the sum is 19.

The square root of 365221 is about 604.3351719038. The cubic root of 365221 is about 71.4801157480.

Adding to 365221 its reverse (122563), we get a palindrome (487784).

The spelling of 365221 in words is "three hundred sixty-five thousand, two hundred twenty-one".