1212210211221 has 12 divisors (see below), whose sum is σ = 1853968558572. Its totient is φ = 760602485376.

The previous prime is 1212210211207. The next prime is 1212210211237. The reversal of 1212210211221 is 1221120122121.

1212210211221 is a `hidden beast` number, since 1 + 21 + 2 + 210 + 211 + 221 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 845563007025 + 366647204196 = 919545^2 + 605514^2 .

It is not a de Polignac number, because 1212210211221 - 2¹⁸ = 1212209949077 is a prime.

It is a super-2 number, since 2×1212210211221² (a number of 25 digits) contains 22 as substring.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 1212210211194 and 1212210211203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212210211271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3961471126 + ... + 3961471431.

It is an arithmetic number, because the mean of its divisors is an integer number (154497379881).

Almost surely, 2^{1212210211221} is an apocalyptic number.

It is an amenable number.

1212210211221 is a deficient number, since it is larger than the sum of its proper divisors (641758347351).

1212210211221 is a wasteful number, since it uses less digits than its factorization.

1212210211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7922942580 (or 7922942577 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 1212210211221 its reverse (1221120122121), we get a palindrome (2433330333342).

The spelling of 1212210211221 in words is "one trillion, two hundred twelve billion, two hundred ten million, two hundred eleven thousand, two hundred twenty-one".