2121121120221 has 12 divisors (see below), whose sum is σ = 3064051358940. Its totient is φ = 1413983943360.

The previous prime is 2121121120169. The next prime is 2121121120231. The reversal of 2121121120221 is 1220211211212.

2121121120221 is a `hidden beast` number, since 2 + 1 + 211 + 211 + 20 + 221 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 948946791321 + 1172174328900 = 974139^2 + 1082670^2 .

It is not a de Polignac number, because 2121121120221 - 2²¹ = 2121119023069 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 2121121120194 and 2121121120203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121121120231) 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, 7928056 + ... + 8191233.

It is an arithmetic number, because the mean of its divisors is an integer number (255337613245).

Almost surely, 2^{2121121120221} is an apocalyptic number.

It is an amenable number.

2121121120221 is a deficient number, since it is larger than the sum of its proper divisors (942930238719).

2121121120221 is a wasteful number, since it uses less digits than its factorization.

2121121120221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16133916 (or 16133913 counting only the distinct ones).

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

Adding to 2121121120221 its reverse (1220211211212), we get a palindrome (3341332331433).

Subtracting from 2121121120221 its reverse (1220211211212), we obtain a palindrome (900909909009).

The spelling of 2121121120221 in words is "two trillion, one hundred twenty-one billion, one hundred twenty-one million, one hundred twenty thousand, two hundred twenty-one".