222221122221 has 16 divisors (see below), whose sum is σ = 338635641344. Its totient is φ = 126978631344.

The previous prime is 222221122213. The next prime is 222221122247. The reversal of 222221122221 is 122221122222.

It is not a de Polignac number, because 222221122221 - 2³ = 222221122213 is a prime.

It is a super-2 number, since 2×222221122221² (a number of 23 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (21).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (222221122261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 399786 + ... + 777348.

It is an arithmetic number, because the mean of its divisors is an integer number (21164727584).

Almost surely, 2^222221122221 is an apocalyptic number.

222221122221 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

222221122221 is a deficient number, since it is larger than the sum of its proper divisors (116414519123).

222221122221 is a wasteful number, since it uses less digits than its factorization.

222221122221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 405600.

The product of its digits is 512, while the sum is 21.

Adding to 222221122221 its reverse (122221122222), we get a palindrome (344442244443).

Subtracting from 222221122221 its reverse (122221122222), we obtain a palindrome (99999999999).

The spelling of 222221122221 in words is "two hundred twenty-two billion, two hundred twenty-one million, one hundred twenty-two thousand, two hundred twenty-one".