11221 has 6 divisors (see below), whose sum is σ = 13110.
Its totient is φ = 9576.
The previous prime is 11213. The next prime is 11239. The reversal of 11221 is 12211.
Adding to 11221 its reverse (12211), we get a palindrome (23432).
Subtracting 11221 from its reverse (12211), we obtain a triangular number (990 = T44).
It can be divided in two parts, 11 and 221, that added together give a palindrome (232).
It can be written as a sum of positive squares in only one way, i.e., 11025 + 196 = 105^2 + 14^2
It is not a de Polignac number, because 11221 - 23 = 11213 is a prime.
It is a Harshad number since it is a multiple of its sum of digits (7).
It is a Duffinian number.
It is a zygodrome in base 4.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (11251) by changing a digit.
It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 66 + ... + 163.
It is an arithmetic number, because the mean of its divisors is an integer number (2185).
211221 is an apocalyptic number.
It is an amenable number.
11221 is a deficient number, since it is larger than the sum of its proper divisors (1889).
11221 is an equidigital number, since it uses as much as digits as its factorization.
11221 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 243 (or 236 counting only the distinct ones).
The product of its digits is 4, while the sum is 7.
The square root of 11221 is about 105.9292216530.
The cubic root of 11221 is about 22.3877537227.
The spelling of 11221 in words is "eleven thousand, two hundred twenty-one", and thus it is an iban number.