211112221221 has 144 divisors (see below), whose sum is σ = 359869910400. Its totient is φ = 118891618560.

The previous prime is 211112221211. The next prime is 211112221249. The reversal of 211112221221 is 122122211112.

211112221221 is a `hidden beast` number, since 211 + 1 + 12 + 221 + 221 = 666.

It is not a de Polignac number, because 211112221221 - 2⁶ = 211112221157 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 211112221194 and 211112221203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211112221211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 144695790 + ... + 144697248.

It is an arithmetic number, because the mean of its divisors is an integer number (2499096600).

Almost surely, 2^211112221221 is an apocalyptic number.

It is an amenable number.

211112221221 is a deficient number, since it is larger than the sum of its proper divisors (148757689179).

211112221221 is a wasteful number, since it uses less digits than its factorization.

211112221221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1672 (or 1658 counting only the distinct ones).

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

Adding to 211112221221 its reverse (122122211112), we get a palindrome (333234432333).

The spelling of 211112221221 in words is "two hundred eleven billion, one hundred twelve million, two hundred twenty-one thousand, two hundred twenty-one".