22121 has 4 divisors (see below), whose sum is σ = 24144.
Its totient is φ = 20100.
The previous prime is 22111. The next prime is 22123. The reversal of 22121 is 12122.
Adding to 22121 its reverse (12122), we get a palindrome (34243).
Subtracting from 22121 its reverse (12122), we obtain a palindrome (9999).
It can be divided in two parts, 221 and 21, that added together give a palindrome (242).
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.
It is a cyclic number.
It is not a de Polignac number, because 22121 - 214 = 5737 is a prime.
It is a Duffinian number.
It is a plaindrome in base 16.
It is a junction number, because it is equal to n+sod(n) for n = 22099 and 22108.
It is not an unprimeable number, because it can be changed into a prime (22123) 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, 995 + ... + 1016.
It is an arithmetic number, because the mean of its divisors is an integer number (6036).
222121 is an apocalyptic number.
22121 is the 80-th centered heptagonal number.
It is an amenable number.
22121 is a deficient number, since it is larger than the sum of its proper divisors (2023).
22121 is a wasteful number, since it uses less digits than its factorization.
22121 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 2022.
The product of its digits is 8, while the sum is 8.
The square root of 22121 is about 148.7313013457.
The cubic root of 22121 is about 28.0716701347.
The spelling of 22121 in words is "twenty-two thousand, one hundred twenty-one", and thus it is an iban number.