255221 has 4 divisors (see below), whose sum is σ = 270252. Its totient is φ = 240192.

The previous prime is 255217. The next prime is 255239. The reversal of 255221 is 122552.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 192721 + 62500 = 439^2 + 250^2 .

It is a cyclic number.

It is not a de Polignac number, because 255221 - 2² = 255217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 15013 = 255221 / (2 + 5 + 5 + 2 + 2 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 255221.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 255221.

It is not an unprimeable number, because it can be changed into a prime (255251) 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, 7490 + ... + 7523.

It is an arithmetic number, because the mean of its divisors is an integer number (67563).

2²⁵⁵²²¹ is an apocalyptic number.

It is an amenable number.

255221 is a deficient number, since it is larger than the sum of its proper divisors (15031).

255221 is a wasteful number, since it uses less digits than its factorization.

255221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15030.

The product of its digits is 200, while the sum is 17.

The square root of 255221 is about 505.1940221341. The cubic root of 255221 is about 63.4315711495.

Adding to 255221 its reverse (122552), we get a palindrome (377773).

The spelling of 255221 in words is "two hundred fifty-five thousand, two hundred twenty-one".