21112220001221 has 8 divisors (see below), whose sum is σ = 21847481157600. Its totient is φ = 20377442416240.

The previous prime is 21112220001217. The next prime is 21112220001241. The reversal of 21112220001221 is 12210002221112.

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 21112220001221 - 2² = 21112220001217 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21112220001221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21112220001211) 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, 120804011 + ... + 120978648.

It is an arithmetic number, because the mean of its divisors is an integer number (2730935144700).

Almost surely, 2^{21112220001221} is an apocalyptic number.

It is an amenable number.

21112220001221 is a deficient number, since it is larger than the sum of its proper divisors (735261156379).

21112220001221 is a wasteful number, since it uses less digits than its factorization.

21112220001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 241785699.

The product of its (nonzero) digits is 64, while the sum is 17.

Adding to 21112220001221 its reverse (12210002221112), we get a palindrome (33322222222333).

The spelling of 21112220001221 in words is "twenty-one trillion, one hundred twelve billion, two hundred twenty million, one thousand, two hundred twenty-one".