221220212221 has 8 divisors (see below), whose sum is σ = 221342898464. Its totient is φ = 221097567600.

The previous prime is 221220212219. The next prime is 221220212251. The reversal of 221220212221 is 122212022122.

221220212221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 221220212221 - 2¹ = 221220212219 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220212201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 17977771 + ... + 17990071.

It is an arithmetic number, because the mean of its divisors is an integer number (27667862308).

Almost surely, 2^221220212221 is an apocalyptic number.

It is an amenable number.

221220212221 is a deficient number, since it is larger than the sum of its proper divisors (122686243).

221220212221 is a wasteful number, since it uses less digits than its factorization.

221220212221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20811.

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 221220212221 its reverse (122212022122), we get a palindrome (343432234343).

The spelling of 221220212221 in words is "two hundred twenty-one billion, two hundred twenty million, two hundred twelve thousand, two hundred twenty-one".