1212211201221 has 48 divisors (see below), whose sum is σ = 1864554597360. Its totient is φ = 757658603520.

The previous prime is 1212211201177. The next prime is 1212211201237. The reversal of 1212211201221 is 1221021122121.

1212211201221 is a `hidden beast` number, since 1 + 21 + 221 + 1 + 201 + 221 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 11543138721 + 1200668062500 = 107439^2 + 1095750^2 .

It is not a de Polignac number, because 1212211201221 - 2¹⁷ = 1212211070149 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 1212211201194 and 1212211201203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212211201261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 890091 + ... + 1793511.

It is an arithmetic number, because the mean of its divisors is an integer number (38844887445).

Almost surely, 2^{1212211201221} is an apocalyptic number.

It is an amenable number.

1212211201221 is a deficient number, since it is larger than the sum of its proper divisors (652343396139).

1212211201221 is a wasteful number, since it uses less digits than its factorization.

1212211201221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 903606 (or 903603 counting only the distinct ones).

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

Adding to 1212211201221 its reverse (1221021122121), we get a palindrome (2433232323342).

The spelling of 1212211201221 in words is "one trillion, two hundred twelve billion, two hundred eleven million, two hundred one thousand, two hundred twenty-one".