21212201212221 has 8 divisors (see below), whose sum is σ = 28283345164800. Its totient is φ = 14141262367232.

The previous prime is 21212201212217. The next prime is 21212201212261. The reversal of 21212201212221 is 12221210221212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21212201212221 - 2² = 21212201212217 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21212201212261) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 51035421 + ... + 51449378.

It is an arithmetic number, because the mean of its divisors is an integer number (3535418145600).

Almost surely, 2^{21212201212221} is an apocalyptic number.

It is an amenable number.

21212201212221 is a deficient number, since it is larger than the sum of its proper divisors (7071143952579).

21212201212221 is a wasteful number, since it uses less digits than its factorization.

21212201212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 102553795.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21212201212221 its reverse (12221210221212), we get a palindrome (33433411433433).

The spelling of 21212201212221 in words is "twenty-one trillion, two hundred twelve billion, two hundred one million, two hundred twelve thousand, two hundred twenty-one".