2120001221221 has 32 divisors (see below), whose sum is σ = 2315568578400. Its totient is φ = 1929246474240.

The previous prime is 2120001221203. The next prime is 2120001221227. The reversal of 2120001221221 is 1221221000212.

It is a happy number.

It can be written as a sum of positive squares in 16 ways, for example, as 258648530625 + 1861352690596 = 508575^2 + 1364314^2 .

It is a cyclic number.

It is not a de Polignac number, because 2120001221221 - 2²³ = 2119992832613 is a prime.

It is a super-3 number, since 3×2120001221221³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2120001221195 and 2120001221204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2120001221227) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 417238401 + ... + 417243481.

It is an arithmetic number, because the mean of its divisors is an integer number (72361518075).

Almost surely, 2^{2120001221221} is an apocalyptic number.

It is an amenable number.

2120001221221 is a deficient number, since it is larger than the sum of its proper divisors (195567357179).

2120001221221 is a wasteful number, since it uses less digits than its factorization.

2120001221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6409.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 2120001221221 its reverse (1221221000212), we get a palindrome (3341222221433).

The spelling of 2120001221221 in words is "two trillion, one hundred twenty billion, one million, two hundred twenty-one thousand, two hundred twenty-one".