2111221222221 has 16 divisors (see below), whose sum is σ = 2893878964800. Its totient is φ = 1368096812928.

The previous prime is 2111221222207. The next prime is 2111221222223. The reversal of 2111221222221 is 1222221221112.

It is not a de Polignac number, because 2111221222221 - 2²² = 2111217027917 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2111221222223) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9219576 + ... + 9445793.

It is an arithmetic number, because the mean of its divisors is an integer number (180867435300).

Almost surely, 2^{2111221222221} is an apocalyptic number.

It is an amenable number.

2111221222221 is a deficient number, since it is larger than the sum of its proper divisors (782657742579).

2111221222221 is a wasteful number, since it uses less digits than its factorization.

2111221222221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18666428.

The product of its digits is 256, while the sum is 21.

Adding to 2111221222221 its reverse (1222221221112), we get a palindrome (3333442443333).

The spelling of 2111221222221 in words is "two trillion, one hundred eleven billion, two hundred twenty-one million, two hundred twenty-two thousand, two hundred twenty-one".