21201121121211 has 32 divisors (see below), whose sum is σ = 31465623744000. Its totient is φ = 14108637011040.

The previous prime is 21201121121207. The next prime is 21201121121221. The reversal of 21201121121211 is 11212112110212.

It is a happy number.

21201121121211 is a `hidden beast` number, since 21 + 201 + 1 + 211 + 21 + 211 = 666.

It is not a de Polignac number, because 21201121121211 - 2² = 21201121121207 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21201121121221) 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, 129480085 + ... + 129643721.

It is an arithmetic number, because the mean of its divisors is an integer number (983300742000).

Almost surely, 2^{21201121121211} is an apocalyptic number.

21201121121211 is a deficient number, since it is larger than the sum of its proper divisors (10264502622789).

21201121121211 is a wasteful number, since it uses less digits than its factorization.

21201121121211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172256 (or 172250 counting only the distinct ones).

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

Adding to 21201121121211 its reverse (11212112110212), we get a palindrome (32413233231423).

The spelling of 21201121121211 in words is "twenty-one trillion, two hundred one billion, one hundred twenty-one million, one hundred twenty-one thousand, two hundred eleven".