12211021221 has 32 divisors (see below), whose sum is σ = 18732748800. Its totient is φ = 6930826560.

The previous prime is 12211021219. The next prime is 12211021247. The reversal of 12211021221 is 12212011221.

It is not a de Polignac number, because 12211021221 - 2¹ = 12211021219 is a prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 12211021221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12211021321) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2110110 + ... + 2115888.

It is an arithmetic number, because the mean of its divisors is an integer number (585398400).

Almost surely, 2^12211021221 is an apocalyptic number.

It is an amenable number.

12211021221 is a deficient number, since it is larger than the sum of its proper divisors (6521727579).

12211021221 is a wasteful number, since it uses less digits than its factorization.

12211021221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6449.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 12211021221 its reverse (12212011221), we get a palindrome (24423032442).

The spelling of 12211021221 in words is "twelve billion, two hundred eleven million, twenty-one thousand, two hundred twenty-one".