205221 has 8 divisors (see below), whose sum is σ = 277984. Its totient is φ = 134640.

The previous prime is 205213. The next prime is 205223. The reversal of 205221 is 122502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 205221 - 2³ = 205213 is a prime.

It is a Duffinian number.

205221 is a lucky number.

It is a junction number, because it is equal to n+sod(n) for n = 205197 and 205206.

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 205221.

It is not an unprimeable number, because it can be changed into a prime (205223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 310 + ... + 711.

It is an arithmetic number, because the mean of its divisors is an integer number (34748).

2²⁰⁵²²¹ is an apocalyptic number.

It is an amenable number.

205221 is a deficient number, since it is larger than the sum of its proper divisors (72763).

205221 is a wasteful number, since it uses less digits than its factorization.

205221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1091.

The product of its (nonzero) digits is 40, while the sum is 12.

The square root of 205221 is about 453.0132448395. The cubic root of 205221 is about 58.9848663665.

Subtracting from 205221 its sum of digits (12), we obtain a square (205209 = 453²).

Adding to 205221 its reverse (122502), we get a palindrome (327723).

The spelling of 205221 in words is "two hundred five thousand, two hundred twenty-one".