211211222120221 has 4 divisors (see below), whose sum is σ = 211211762085244. Its totient is φ = 211210682155200.

The previous prime is 211211222120219. The next prime is 211211222120263. The reversal of 211211222120221 is 122021222112112.

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 51722864643321 + 159488357476900 = 7191861^2 + 12628870^2 .

It is a cyclic number.

It is not a de Polignac number, because 211211222120221 - 2¹ = 211211222120219 is a prime.

It is a super-2 number, since 2×211211222120221² (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 = 211211222120192 and 211211222120201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211211222120281) 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, 269395350 + ... + 270178231.

It is an arithmetic number, because the mean of its divisors is an integer number (52802940521311).

Almost surely, 2^{211211222120221} is an apocalyptic number.

It is an amenable number.

211211222120221 is a deficient number, since it is larger than the sum of its proper divisors (539965023).

211211222120221 is an equidigital number, since it uses as much as digits as its factorization.

211211222120221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 539965022.

The product of its (nonzero) digits is 256, while the sum is 22.

Adding to 211211222120221 its reverse (122021222112112), we get a palindrome (333232444232333).

The spelling of 211211222120221 in words is "two hundred eleven trillion, two hundred eleven billion, two hundred twenty-two million, one hundred twenty thousand, two hundred twenty-one".