211212220221 has 16 divisors (see below), whose sum is σ = 314216236800. Its totient is φ = 140218987104.

The previous prime is 211212220183. The next prime is 211212220229. The reversal of 211212220221 is 122022212112.

It is a happy number.

211212220221 is a `hidden beast` number, since 2 + 11 + 212 + 220 + 221 = 666.

It is not a de Polignac number, because 211212220221 - 2¹⁸ = 211211958077 is a prime.

It is a super-2 number, since 2×211212220221² (a number of 23 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 211212220194 and 211212220203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (211212220229) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16358976 + ... + 16371881.

It is an arithmetic number, because the mean of its divisors is an integer number (19638514800).

Almost surely, 2^211212220221 is an apocalyptic number.

It is an amenable number.

211212220221 is a deficient number, since it is larger than the sum of its proper divisors (103004016579).

211212220221 is a wasteful number, since it uses less digits than its factorization.

211212220221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32731105 (or 32731099 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 18.

Adding to 211212220221 its reverse (122022212112), we get a palindrome (333234432333).

The spelling of 211212220221 in words is "two hundred eleven billion, two hundred twelve million, two hundred twenty thousand, two hundred twenty-one".