2120121221221 has 16 divisors (see below), whose sum is σ = 2253576291120. Its totient is φ = 1994545013760.

The previous prime is 2120121221161. The next prime is 2120121221269. The reversal of 2120121221221 is 1221221210212.

It can be written as a sum of positive squares in 8 ways, for example, as 119837130625 + 2000284090596 = 346175^2 + 1414314^2 .

It is not a de Polignac number, because 2120121221221 - 2¹³ = 2120121213029 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2120121222221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11409165 + ... + 11593501.

It is an arithmetic number, because the mean of its divisors is an integer number (140848518195).

Almost surely, 2^{2120121221221} is an apocalyptic number.

It is an amenable number.

2120121221221 is a deficient number, since it is larger than the sum of its proper divisors (133455069899).

2120121221221 is an equidigital number, since it uses as much as digits as its factorization.

2120121221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 186729 (or 186695 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 2120121221221 its reverse (1221221210212), we get a palindrome (3341342431433).

The spelling of 2120121221221 in words is "two trillion, one hundred twenty billion, one hundred twenty-one million, two hundred twenty-one thousand, two hundred twenty-one".