212112221 has 4 divisors (see below), whose sum is σ = 214212444. Its totient is φ = 210012000.

The previous prime is 212112169. The next prime is 212112223. The reversal of 212112221 is 122211212.

212112221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 200647225 + 11464996 = 14165^2 + 3386^2 .

It is a cyclic number.

It is not a de Polignac number, because 212112221 - 2²² = 207917917 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 212112196 and 212112205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212112223) 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, 1049960 + ... + 1050161.

It is an arithmetic number, because the mean of its divisors is an integer number (53553111).

Almost surely, 2^212112221 is an apocalyptic number.

It is an amenable number.

212112221 is a deficient number, since it is larger than the sum of its proper divisors (2100223).

212112221 is a wasteful number, since it uses less digits than its factorization.

212112221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2100222.

The product of its digits is 32, while the sum is 14.

The square root of 212112221 is about 14564.0729536761. The cubic root of 212112221 is about 596.3783884958.

Adding to 212112221 its reverse (122211212), we get a palindrome (334323433).

It can be divided in two parts, 21211 and 2221, that added together give a palindrome (23432).

The spelling of 212112221 in words is "two hundred twelve million, one hundred twelve thousand, two hundred twenty-one".