21211222012221 has 8 divisors (see below), whose sum is σ = 28389164063040. Its totient is φ = 14087047318112.

The previous prime is 21211222012199. The next prime is 21211222012259. The reversal of 21211222012221 is 12221022211212.

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 21211222012221 - 2⁷ = 21211222012093 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211222012121) 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, 13441838256 + ... + 13441839833.

It is an arithmetic number, because the mean of its divisors is an integer number (3548645507880).

Almost surely, 2^{21211222012221} is an apocalyptic number.

It is an amenable number.

21211222012221 is a deficient number, since it is larger than the sum of its proper divisors (7177942050819).

21211222012221 is a wasteful number, since it uses less digits than its factorization.

21211222012221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26883678355.

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

Adding to 21211222012221 its reverse (12221022211212), we get a palindrome (33432244223433).

The spelling of 21211222012221 in words is "twenty-one trillion, two hundred eleven billion, two hundred twenty-two million, twelve thousand, two hundred twenty-one".