212221111 has 4 divisors (see below), whose sum is σ = 212480424. Its totient is φ = 211961800.

The previous prime is 212221067. The next prime is 212221153. The reversal of 212221111 is 111122212.

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

It is a cyclic number.

It is not a de Polignac number, because 212221111 - 2²⁵ = 178666679 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212221091 and 212221100.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212221181) 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, 128425 + ... + 130066.

It is an arithmetic number, because the mean of its divisors is an integer number (53120106).

Almost surely, 2^212221111 is an apocalyptic number.

212221111 is a deficient number, since it is larger than the sum of its proper divisors (259313).

212221111 is an equidigital number, since it uses as much as digits as its factorization.

212221111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259312.

The product of its digits is 16, while the sum is 13.

The square root of 212221111 is about 14567.8107826811. The cubic root of 212221111 is about 596.4804233733.

Adding to 212221111 its reverse (111122212), we get a palindrome (323343323).

The spelling of 212221111 in words is "two hundred twelve million, two hundred twenty-one thousand, one hundred eleven".