21122120111211 has 72 divisors (see below), whose sum is σ = 37390342841280. Its totient is φ = 11424892673376.

The previous prime is 21122120111201. The next prime is 21122120111227. The reversal of 21122120111211 is 11211102122112.

It is a happy number.

21122120111211 is a `hidden beast` number, since 21 + 1 + 221 + 201 + 11 + 211 = 666.

It is not a de Polignac number, because 21122120111211 - 2³⁰ = 21121046369387 is a prime.

It is a super-2 number, since 2×21122120111211² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21122120111201) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 8884020 + ... + 11007726.

It is an arithmetic number, because the mean of its divisors is an integer number (519310317240).

Almost surely, 2^{21122120111211} is an apocalyptic number.

21122120111211 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21122120111211 is a deficient number, since it is larger than the sum of its proper divisors (16268222730069).

21122120111211 is a wasteful number, since it uses less digits than its factorization.

21122120111211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2124933 (or 2124923 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 18.

Adding to 21122120111211 its reverse (11211102122112), we get a palindrome (32333222233323).

The spelling of 21122120111211 in words is "twenty-one trillion, one hundred twenty-two billion, one hundred twenty million, one hundred eleven thousand, two hundred eleven".