221311101221 has 4 divisors (see below), whose sum is σ = 252926972832. Its totient is φ = 189695229612.

The previous prime is 221311101197. The next prime is 221311101223. The reversal of 221311101221 is 122101113122.

It is a happy number.

221311101221 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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, and also an emirpimes, since its reverse is a distinct semiprime: 122101113122 = 2 ⋅61050556561.

It is a de Polignac number, because none of the positive numbers 2^k-221311101221 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 221311101221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221311101223) 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 3 ways as a sum of consecutive naturals, for example, 15807935795 + ... + 15807935808.

It is an arithmetic number, because the mean of its divisors is an integer number (63231743208).

Almost surely, 2^221311101221 is an apocalyptic number.

It is an amenable number.

221311101221 is a deficient number, since it is larger than the sum of its proper divisors (31615871611).

221311101221 is an equidigital number, since it uses as much as digits as its factorization.

221311101221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31615871610.

The product of its (nonzero) digits is 48, while the sum is 17.

Adding to 221311101221 its reverse (122101113122), we get a palindrome (343412214343).

The spelling of 221311101221 in words is "two hundred twenty-one billion, three hundred eleven million, one hundred one thousand, two hundred twenty-one".