211110111221 has 4 divisors (see below), whose sum is σ = 213200310444. Its totient is φ = 209019912000.

The previous prime is 211110111211. The next prime is 211110111227. The reversal of 211110111221 is 122111011112.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 189237180196 + 21872931025 = 435014^2 + 147895^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-211110111221 is a prime.

It is a super-2 number, since 2×211110111221² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 211110111196 and 211110111205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211110111227) 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, 1045099460 + ... + 1045099661.

It is an arithmetic number, because the mean of its divisors is an integer number (53300077611).

Almost surely, 2^211110111221 is an apocalyptic number.

It is an amenable number.

211110111221 is a deficient number, since it is larger than the sum of its proper divisors (2090199223).

211110111221 is a wasteful number, since it uses less digits than its factorization.

211110111221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2090199222.

The product of its (nonzero) digits is 8, while the sum is 14.

Adding to 211110111221 its reverse (122111011112), we get a palindrome (333221122333).

The spelling of 211110111221 in words is "two hundred eleven billion, one hundred ten million, one hundred eleven thousand, two hundred twenty-one".