2121201220221 has 12 divisors (see below), whose sum is σ = 3071957211648. Its totient is φ = 1410441888264.

The previous prime is 2121201220199. The next prime is 2121201220247. The reversal of 2121201220221 is 1220221021212.

It is a happy number.

2121201220221 is a `hidden beast` number, since 2 + 1 + 21 + 201 + 220 + 221 = 666.

It is not a de Polignac number, because 2121201220221 - 2¹³ = 2121201212029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2121201220194 and 2121201220203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121201220321) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 307684575 + ... + 307691468.

It is an arithmetic number, because the mean of its divisors is an integer number (255996434304).

Almost surely, 2^{2121201220221} is an apocalyptic number.

It is an amenable number.

2121201220221 is a deficient number, since it is larger than the sum of its proper divisors (950755991427).

2121201220221 is a wasteful number, since it uses less digits than its factorization.

2121201220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 615376432 (or 615376429 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 2121201220221 its reverse (1220221021212), we get a palindrome (3341422241433).

It can be divided in two parts, 212120 and 1220221, that added together give a palindrome (1432341).

The spelling of 2121201220221 in words is "two trillion, one hundred twenty-one billion, two hundred one million, two hundred twenty thousand, two hundred twenty-one".