221210110211221 has 4 divisors (see below), whose sum is σ = 221660639967744. Its totient is φ = 220759580454700.

The previous prime is 221210110211159. The next prime is 221210110211287. The reversal of 221210110211221 is 122112011012122.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 221210110211221 - 2⁷ = 221210110211093 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 (221210110214221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225264877525 + ... + 225264878506.

It is an arithmetic number, because the mean of its divisors is an integer number (55415159991936).

Almost surely, 2^{221210110211221} is an apocalyptic number.

It is an amenable number.

221210110211221 is a deficient number, since it is larger than the sum of its proper divisors (450529756523).

221210110211221 is an equidigital number, since it uses as much as digits as its factorization.

221210110211221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 450529756522.

The product of its (nonzero) digits is 64, while the sum is 19.

Adding to 221210110211221 its reverse (122112011012122), we get a palindrome (343322121223343).

The spelling of 221210110211221 in words is "two hundred twenty-one trillion, two hundred ten billion, one hundred ten million, two hundred eleven thousand, two hundred twenty-one".