211211001220221 has 10 divisors (see below), whose sum is σ = 315512730217982. Its totient is φ = 140807334146760.

The previous prime is 211211001220217. The next prime is 211211001220243. The reversal of 211211001220221 is 122022100112112.

211211001220221 is a `hidden beast` number, since 2 + 1 + 121 + 100 + 1 + 220 + 221 = 666.

It can be written as a sum of positive squares in only one way, i.e., 194107896572121 + 17103104648100 = 13932261^2 + 4135590^2 .

It is not a de Polignac number, because 211211001220221 - 2² = 211211001220217 is a prime.

It is a super-2 number, since 2×211211001220221² (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 = 211211001220194 and 211211001220203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211211001220291) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 1303771612390 + ... + 1303771612551.

Almost surely, 2^{211211001220221} is an apocalyptic number.

It is an amenable number.

211211001220221 is a deficient number, since it is larger than the sum of its proper divisors (104301728997761).

211211001220221 is an equidigital number, since it uses as much as digits as its factorization.

211211001220221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2607543224953 (or 2607543224944 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 18.

Adding to 211211001220221 its reverse (122022100112112), we get a palindrome (333233101332333).

The spelling of 211211001220221 in words is "two hundred eleven trillion, two hundred eleven billion, one million, two hundred twenty thousand, two hundred twenty-one".