211212111102221 has 4 divisors (see below), whose sum is σ = 211997286236700. Its totient is φ = 210426935967744.

The previous prime is 211212111102203. The next prime is 211212111102229. The reversal of 211212111102221 is 122201111212112.

It is a happy number.

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 72600811813321 + 138611299288900 = 8520611^2 + 11773330^2 .

It is a cyclic number.

It is not a de Polignac number, because 211212111102221 - 2³⁰ = 211211037360397 is a prime.

It is a super-2 number, since 2×211212111102221² (a number of 29 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 = 211212111102193 and 211212111102202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211212111102229) 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 3 ways as a sum of consecutive naturals, for example, 392587566836 + ... + 392587567373.

It is an arithmetic number, because the mean of its divisors is an integer number (52999321559175).

Almost surely, 2^{211212111102221} is an apocalyptic number.

It is an amenable number.

211212111102221 is a deficient number, since it is larger than the sum of its proper divisors (785175134479).

211212111102221 is an equidigital number, since it uses as much as digits as its factorization.

211212111102221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 785175134478.

The product of its (nonzero) digits is 64, while the sum is 20.

Adding to 211212111102221 its reverse (122201111212112), we get a palindrome (333413222314333).

The spelling of 211212111102221 in words is "two hundred eleven trillion, two hundred twelve billion, one hundred eleven million, one hundred two thousand, two hundred twenty-one".