12221 has 6 divisors (see below), whose sum is σ = 13566. Its totient is φ = 11000.

The previous prime is 12211. The next prime is 12227.

12221 = T₉ + T₁₀ + ... + T₄₁.

12221 is nontrivially palindromic in base 10.

It can be written as a sum of positive squares in only one way, i.e., 12100 + 121 = 110^2 + 11^2 .

It is not a de Polignac number, because 12221 - 2⁶ = 12157 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a nialpdrome in base 11.

It is a junction number, because it is equal to n+sod(n) for n = 12199 and 12208.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 71 + ... + 171.

It is an arithmetic number, because the mean of its divisors is an integer number (2261).

2¹²²²¹ is an apocalyptic number.

12221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

12221 is a deficient number, since it is larger than the sum of its proper divisors (1345).

12221 is a wasteful number, since it uses less digits than its factorization.

12221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 123 (or 112 counting only the distinct ones).

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

The square root of 12221 is about 110.5486318323. The cubic root of 12221 is about 23.0339762496.

It can be divided in two parts, 1 and 2221, that added together give a palindrome (2222).

The spelling of 12221 in words is "twelve thousand, two hundred twenty-one", and thus it is an iban number.