211211100120221 has 4 divisors (see below), whose sum is σ = 223635282480252. Its totient is φ = 198786917760192.

The previous prime is 211211100120199. The next prime is 211211100120247. The reversal of 211211100120221 is 122021001112112.

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 83769263028025 + 127441837092196 = 9152555^2 + 11289014^2 .

It is a cyclic number.

It is not a de Polignac number, because 211211100120221 - 2³⁰ = 211210026378397 is a prime.

It is a super-2 number, since 2×211211100120221² (a number of 29 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (17), and also a Moran number because the ratio is a prime number: 12424182360013 = 211211100120221 / (2 + 1 + 1 + 2 + 1 + 1 + 1 + 0 + 0 + 1 + 2 + 0 + 2 + 2 + 1).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 211211100120221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211211100122221) 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, 6212091179990 + ... + 6212091180023.

It is an arithmetic number, because the mean of its divisors is an integer number (55908820620063).

Almost surely, 2^{211211100120221} is an apocalyptic number.

It is an amenable number.

211211100120221 is a deficient number, since it is larger than the sum of its proper divisors (12424182360031).

211211100120221 is a wasteful number, since it uses less digits than its factorization.

211211100120221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12424182360030.

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 211211100120221 its reverse (122021001112112), we get a palindrome (333232101232333).

The spelling of 211211100120221 in words is "two hundred eleven trillion, two hundred eleven billion, one hundred million, one hundred twenty thousand, two hundred twenty-one".