1212211221021 has 24 divisors (see below), whose sum is σ = 1904077411704. Its totient is φ = 740046274560.

The previous prime is 1212211221019. The next prime is 1212211221059. The reversal of 1212211221021 is 1201221122121.

1212211221021 is a `hidden beast` number, since 1 + 212 + 211 + 221 + 0 + 21 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1003481024121 + 208730196900 = 1001739^2 + 456870^2 .

It is not a de Polignac number, because 1212211221021 - 2¹ = 1212211221019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1212211220985 and 1212211221003.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212211221121) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 107061220 + ... + 107072541.

It is an arithmetic number, because the mean of its divisors is an integer number (79336558821).

Almost surely, 2^{1212211221021} is an apocalyptic number.

It is an amenable number.

1212211221021 is a deficient number, since it is larger than the sum of its proper divisors (691866190683).

1212211221021 is a wasteful number, since it uses less digits than its factorization.

1212211221021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 214133821 (or 214133818 counting only the distinct ones).

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

Adding to 1212211221021 its reverse (1201221122121), we get a palindrome (2413432343142).

The spelling of 1212211221021 in words is "one trillion, two hundred twelve billion, two hundred eleven million, two hundred twenty-one thousand, twenty-one".