12210021221 has 4 divisors (see below), whose sum is σ = 12210279744. Its totient is φ = 12209762700.

The previous prime is 12210021203. The next prime is 12210021323. The reversal of 12210021221 is 12212001221.

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 12210021221 - 2¹⁰ = 12210020197 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 = 12210021196 and 12210021205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12210021821) 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, 35975 + ... + 160356.

It is an arithmetic number, because the mean of its divisors is an integer number (3052569936).

Almost surely, 2^12210021221 is an apocalyptic number.

It is an amenable number.

12210021221 is a deficient number, since it is larger than the sum of its proper divisors (258523).

12210021221 is an equidigital number, since it uses as much as digits as its factorization.

12210021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258522.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 12210021221 its reverse (12212001221), we get a palindrome (24422022442).

The spelling of 12210021221 in words is "twelve billion, two hundred ten million, twenty-one thousand, two hundred twenty-one".