21221111021211 has 24 divisors (see below), whose sum is σ = 30962477347776. Its totient is φ = 14004497270400.

The previous prime is 21221111021191. The next prime is 21221111021213. The reversal of 21221111021211 is 11212011112212.

It is a happy number.

21221111021211 is a `hidden beast` number, since 212 + 211 + 1 + 10 + 21 + 211 = 666.

It is not a de Polignac number, because 21221111021211 - 2⁵ = 21221111021179 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21221111021213) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2131711 + ... + 6854663.

It is an arithmetic number, because the mean of its divisors is an integer number (1290103222824).

Almost surely, 2^{21221111021211} is an apocalyptic number.

21221111021211 is a deficient number, since it is larger than the sum of its proper divisors (9741366326565).

21221111021211 is a wasteful number, since it uses less digits than its factorization.

21221111021211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4728003 (or 4728000 counting only the distinct ones).

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

Adding to 21221111021211 its reverse (11212011112212), we get a palindrome (32433122133423).

The spelling of 21221111021211 in words is "twenty-one trillion, two hundred twenty-one billion, one hundred eleven million, twenty-one thousand, two hundred eleven".