2011222221221 has 4 divisors (see below), whose sum is σ = 2011225113612. Its totient is φ = 2011219328832.

The previous prime is 2011222221193. The next prime is 2011222221289. The reversal of 2011222221221 is 1221222221102.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 752450418721 + 1258771802500 = 867439^2 + 1121950^2 .

It is a cyclic number.

It is not a de Polignac number, because 2011222221221 - 2³⁴ = 1994042352037 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2011222221193 and 2011222221202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2011222211221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 298151 + ... + 2027643.

It is an arithmetic number, because the mean of its divisors is an integer number (502806278403).

Almost surely, 2^{2011222221221} is an apocalyptic number.

It is an amenable number.

2011222221221 is a deficient number, since it is larger than the sum of its proper divisors (2892391).

2011222221221 is a wasteful number, since it uses less digits than its factorization.

2011222221221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2892390.

The product of its (nonzero) digits is 256, while the sum is 20.

Adding to 2011222221221 its reverse (1221222221102), we get a palindrome (3232444442323).

The spelling of 2011222221221 in words is "two trillion, eleven billion, two hundred twenty-two million, two hundred twenty-one thousand, two hundred twenty-one".