211111222221 has 48 divisors (see below), whose sum is σ = 325405491840. Its totient is φ = 131508489600.

The previous prime is 211111222219. The next prime is 211111222261. The reversal of 211111222221 is 122222111112.

211111222221 is a `hidden beast` number, since 211 + 1 + 11 + 222 + 221 = 666.

It is not a de Polignac number, because 211111222221 - 2¹ = 211111222219 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 211111222194 and 211111222203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211111222261) 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, 4519035 + ... + 4565511.

It is an arithmetic number, because the mean of its divisors is an integer number (6779281080).

Almost surely, 2^211111222221 is an apocalyptic number.

It is an amenable number.

211111222221 is a deficient number, since it is larger than the sum of its proper divisors (114294269619).

211111222221 is a wasteful number, since it uses less digits than its factorization.

211111222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 46866 (or 46863 counting only the distinct ones).

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

Adding to 211111222221 its reverse (122222111112), we get a palindrome (333333333333).

The spelling of 211111222221 in words is "two hundred eleven billion, one hundred eleven million, two hundred twenty-two thousand, two hundred twenty-one".