212111111221 has 8 divisors (see below), whose sum is σ = 228965518080. Its totient is φ = 195892719792.

The previous prime is 212111111209. The next prime is 212111111237. The reversal of 212111111221 is 122111111212.

212111111221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 212111111221 - 2⁵ = 212111111189 is a prime.

It is a super-2 number, since 2×212111111221² (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 = 212111111195 and 212111111204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (212111111021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 159003165 + ... + 159004498.

It is an arithmetic number, because the mean of its divisors is an integer number (28620689760).

Almost surely, 2^212111111221 is an apocalyptic number.

It is an amenable number.

212111111221 is a deficient number, since it is larger than the sum of its proper divisors (16854406859).

212111111221 is a wasteful number, since it uses less digits than its factorization.

212111111221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 318007715.

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

Adding to 212111111221 its reverse (122111111212), we get a palindrome (334222222433).

Subtracting from 212111111221 its reverse (122111111212), we obtain a palindrome (90000000009).

The spelling of 212111111221 in words is "two hundred twelve billion, one hundred eleven million, one hundred eleven thousand, two hundred twenty-one".