2121120213221 has 48 divisors (see below), whose sum is σ = 2308496526000. Its totient is φ = 1948008185856.

The previous prime is 2121120213217. The next prime is 2121120213257. The reversal of 2121120213221 is 1223120211212.

It can be written as a sum of positive squares in 8 ways, for example, as 295676025121 + 1825444188100 = 543761^2 + 1351090^2 .

It is not a de Polignac number, because 2121120213221 - 2² = 2121120213217 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2121120213193 and 2121120213202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2121120213281) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 380877125 + ... + 380882693.

It is an arithmetic number, because the mean of its divisors is an integer number (48093677625).

Almost surely, 2^{2121120213221} is an apocalyptic number.

It is an amenable number.

2121120213221 is a deficient number, since it is larger than the sum of its proper divisors (187376312779).

2121120213221 is a wasteful number, since it uses less digits than its factorization.

2121120213221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5926 (or 5907 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 20.

Adding to 2121120213221 its reverse (1223120211212), we get a palindrome (3344240424433).

The spelling of 2121120213221 in words is "two trillion, one hundred twenty-one billion, one hundred twenty million, two hundred thirteen thousand, two hundred twenty-one".