221222222221 has 32 divisors (see below), whose sum is σ = 303087456000. Its totient is φ = 159120843840.

The previous prime is 221222222209. The next prime is 221222222233. The reversal of 221222222221 is 122222222122.

It is an interprime number because it is at equal distance from previous prime (221222222209) and next prime (221222222233).

It is not a de Polignac number, because 221222222221 - 2¹³ = 221222214029 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221222222192 and 221222222201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221222222251) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2206066 + ... + 2304163.

It is an arithmetic number, because the mean of its divisors is an integer number (9471483000).

Almost surely, 2^221222222221 is an apocalyptic number.

It is an amenable number.

221222222221 is a deficient number, since it is larger than the sum of its proper divisors (81865233779).

221222222221 is a wasteful number, since it uses less digits than its factorization.

221222222221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4510274 (or 4510260 counting only the distinct ones).

The product of its digits is 1024, while the sum is 22.

Adding to 221222222221 its reverse (122222222122), we get a palindrome (343444444343).

Subtracting from 221222222221 its reverse (122222222122), we obtain a palindrome (99000000099).

It can be divided in two parts, 22 and 1222222221, that multiplied together give a palindrome (26888888862).

The spelling of 221222222221 in words is "two hundred twenty-one billion, two hundred twenty-two million, two hundred twenty-two thousand, two hundred twenty-one".