211211221221121 has 16 divisors (see below), whose sum is σ = 238503097909440. Its totient is φ = 185275909900480.

The previous prime is 211211221221107. The next prime is 211211221221131. The reversal of 211211221221121 is 121122122112112.

It is a cyclic number.

It is not a de Polignac number, because 211211221221121 - 2⁹ = 211211221220609 is a prime.

It is a super-2 number, since 2×211211221221121² (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 = 211211221221092 and 211211221221101.

It is not an unprimeable number, because it can be changed into a prime (211211221221131) 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, 201708751 + ... + 202753156.

It is an arithmetic number, because the mean of its divisors is an integer number (14906443619340).

Almost surely, 2^{211211221221121} is an apocalyptic number.

It is an amenable number.

211211221221121 is a deficient number, since it is larger than the sum of its proper divisors (27291876688319).

211211221221121 is a wasteful number, since it uses less digits than its factorization.

211211221221121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 404463584.

The product of its digits is 128, while the sum is 22.

Adding to 211211221221121 its reverse (121122122112112), we get a palindrome (332333343333233).

The spelling of 211211221221121 in words is "two hundred eleven trillion, two hundred eleven billion, two hundred twenty-one million, two hundred twenty-one thousand, one hundred twenty-one".