21211121101221 has 32 divisors (see below), whose sum is σ = 31449949872000. Its totient is φ = 14129020771200.

The previous prime is 21211121101217. The next prime is 21211121101279. The reversal of 21211121101221 is 12210112111212.

It is a happy number.

21211121101221 is a `hidden beast` number, since 21 + 211 + 1 + 211 + 0 + 1 + 221 = 666.

It is not a de Polignac number, because 21211121101221 - 2² = 21211121101217 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21211121101194 and 21211121101203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211121101021) 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, 242571510 + ... + 242658936.

It is an arithmetic number, because the mean of its divisors is an integer number (982810933500).

Almost surely, 2^{21211121101221} is an apocalyptic number.

It is an amenable number.

21211121101221 is a deficient number, since it is larger than the sum of its proper divisors (10238828770779).

21211121101221 is a wasteful number, since it uses less digits than its factorization.

21211121101221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94786 (or 94780 counting only the distinct ones).

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

Adding to 21211121101221 its reverse (12210112111212), we get a palindrome (33421233212433).

The spelling of 21211121101221 in words is "twenty-one trillion, two hundred eleven billion, one hundred twenty-one million, one hundred one thousand, two hundred twenty-one".