21212111201211 has 32 divisors (see below), whose sum is σ = 35920323115520. Its totient is φ = 12119303750112.

The previous prime is 21212111201207. The next prime is 21212111201221. The reversal of 21212111201211 is 11210211121212.

It is a happy number.

21212111201211 is a `hidden beast` number, since 2 + 121 + 211 + 120 + 1 + 211 = 666.

It is not a de Polignac number, because 21212111201211 - 2² = 21212111201207 is a prime.

It is a super-2 number, since 2×21212111201211² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21212111201201) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7600885 + ... + 10009878.

It is an arithmetic number, because the mean of its divisors is an integer number (1122510097360).

Almost surely, 2^{21212111201211} is an apocalyptic number.

21212111201211 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

21212111201211 is a deficient number, since it is larger than the sum of its proper divisors (14708211914309).

21212111201211 is a wasteful number, since it uses less digits than its factorization.

21212111201211 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17617152 (or 17617146 counting only the distinct ones).

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

Adding to 21212111201211 its reverse (11210211121212), we get a palindrome (32422322322423).

The spelling of 21212111201211 in words is "twenty-one trillion, two hundred twelve billion, one hundred eleven million, two hundred one thousand, two hundred eleven".