211211210121 has 12 divisors (see below), whose sum is σ = 286468996272. Its totient is φ = 138420899224.

The previous prime is 211211210083. The next prime is 211211210141. The reversal of 211211210121 is 121012112112.

It is a happy number.

It is not a de Polignac number, because 211211210121 - 2⁹ = 211211209609 is a prime.

It is a super-2 number, since 2×211211210121² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 211211210121.

It is not an unprimeable number, because it can be changed into a prime (211211210141) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 10102131 + ... + 10123016.

It is an arithmetic number, because the mean of its divisors is an integer number (23872416356).

Almost surely, 2^211211210121 is an apocalyptic number.

It is an amenable number.

211211210121 is a deficient number, since it is larger than the sum of its proper divisors (75257786151).

211211210121 is an equidigital number, since it uses as much as digits as its factorization.

211211210121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20225268 (or 20225209 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 211211210121 its reverse (121012112112), we get a palindrome (332223322233).

The spelling of 211211210121 in words is "two hundred eleven billion, two hundred eleven million, two hundred ten thousand, one hundred twenty-one".