221220101221 has 4 divisors (see below), whose sum is σ = 252822972832. Its totient is φ = 189617229612.

The previous prime is 221220101209. The next prime is 221220101239. The reversal of 221220101221 is 122101022122.

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 221220101221 - 2⁷ = 221220101093 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 221220101195 and 221220101204.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221220101251) 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, 15801435795 + ... + 15801435808.

It is an arithmetic number, because the mean of its divisors is an integer number (63205743208).

Almost surely, 2^221220101221 is an apocalyptic number.

It is an amenable number.

221220101221 is a deficient number, since it is larger than the sum of its proper divisors (31602871611).

221220101221 is an equidigital number, since it uses as much as digits as its factorization.

221220101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31602871610.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 221220101221 its reverse (122101022122), we get a palindrome (343321123343).

The spelling of 221220101221 in words is "two hundred twenty-one billion, two hundred twenty million, one hundred one thousand, two hundred twenty-one".