201221 has 4 divisors (see below), whose sum is σ = 207744. Its totient is φ = 194700.

The previous prime is 201211. The next prime is 201233. The reversal of 201221 is 122102.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 122102 = 2 ⋅61051.

It is a cyclic number.

It is not a de Polignac number, because 201221 - 2¹⁴ = 184837 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 201199 and 201208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (201211) 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, 3215 + ... + 3276.

It is an arithmetic number, because the mean of its divisors is an integer number (51936).

2²⁰¹²²¹ is an apocalyptic number.

It is an amenable number.

201221 is a deficient number, since it is larger than the sum of its proper divisors (6523).

201221 is an equidigital number, since it uses as much as digits as its factorization.

201221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6522.

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 201221 is about 448.5766378223. The cubic root of 201221 is about 58.5991209240.

Adding to 201221 its reverse (122102), we get a palindrome (323323).

The spelling of 201221 in words is "two hundred one thousand, two hundred twenty-one", and thus it is an iban number.