1212202221221 has 16 divisors (see below), whose sum is σ = 1311757010928. Its totient is φ = 1115992857600.

The previous prime is 1212202221203. The next prime is 1212202221247. The reversal of 1212202221221 is 1221222022121.

It can be written as a sum of positive squares in 8 ways, for example, as 626424760900 + 585777460321 = 791470^2 + 765361^2 .

It is a cyclic number.

It is not a de Polignac number, because 1212202221221 - 2³⁴ = 1195022352037 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1212202221193 and 1212202221202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1212202221421) 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 15 ways as a sum of consecutive naturals, for example, 3041450 + ... + 3416843.

It is an arithmetic number, because the mean of its divisors is an integer number (81984813183).

Almost surely, 2^{1212202221221} is an apocalyptic number.

It is an amenable number.

1212202221221 is a deficient number, since it is larger than the sum of its proper divisors (99554789707).

1212202221221 is a wasteful number, since it uses less digits than its factorization.

1212202221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6458552.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 1212202221221 its reverse (1221222022121), we get a palindrome (2433424243342).

The spelling of 1212202221221 in words is "one trillion, two hundred twelve billion, two hundred two million, two hundred twenty-one thousand, two hundred twenty-one".