222221211221 has 4 divisors (see below), whose sum is σ = 223106554944. Its totient is φ = 221335867500.

The previous prime is 222221211059. The next prime is 222221211283. The reversal of 222221211221 is 122112122222.

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: 122112122222 = 2 ⋅61056061111.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-222221211221 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 222221211193 and 222221211202.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (222221211521) 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, 442671485 + ... + 442671986.

It is an arithmetic number, because the mean of its divisors is an integer number (55776638736).

Almost surely, 2^222221211221 is an apocalyptic number.

It is an amenable number.

222221211221 is a deficient number, since it is larger than the sum of its proper divisors (885343723).

222221211221 is an equidigital number, since it uses as much as digits as its factorization.

222221211221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 885343722.

The product of its digits is 256, while the sum is 20.

Adding to 222221211221 its reverse (122112122222), we get a palindrome (344333333443).

The spelling of 222221211221 in words is "two hundred twenty-two billion, two hundred twenty-one million, two hundred eleven thousand, two hundred twenty-one".