12021 has 4 divisors (see below), whose sum is σ = 16032.
Its totient is φ = 8012.
The previous prime is 12011. The next prime is 12037.
It is a happy number.
12021 is nontrivially palindromic in base 10.
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 12021 - 211 = 9973 is a prime.
It is a D-number.
It is a Curzon number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (12011) 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, 2001 + ... + 2006.
It is an arithmetic number, because the mean of its divisors is an integer number (4008).
212021 is an apocalyptic number.
It is an amenable number.
12021 is a deficient number, since it is larger than the sum of its proper divisors (4011).
12021 is an equidigital number, since it uses as much as digits as its factorization.
12021 is an evil number, because the sum of its binary digits is even.
The sum of its prime factors is 4010.
The product of its (nonzero) digits is 4, while the sum is 6.
The square root of 12021 is about 109.6403210502.
The cubic root of 12021 is about 22.9076320677.
It can be divided in two parts, 120 and 21, that added together give a palindrome (141).
The spelling of 12021 in words is "twelve thousand, twenty-one", and thus it is an iban number.