221222212120 has 128 divisors (see below), whose sum is σ = 616039603200. Its totient is φ = 69621843456.

The previous prime is 221222212037. The next prime is 221222212129. The reversal of 221222212120 is 21212222122.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221222212129) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 481797 + ... + 821323.

It is an arithmetic number, because the mean of its divisors is an integer number (4812809400).

Almost surely, 2^221222212120 is an apocalyptic number.

221222212120 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 221222212120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (308019801600).

221222212120 is an abundant number, since it is smaller than the sum of its proper divisors (394817391080).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

221222212120 is a wasteful number, since it uses less digits than its factorization.

221222212120 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339737 (or 339733 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 19.

Adding to 221222212120 its reverse (21212222122), we get a palindrome (242434434242).

The spelling of 221222212120 in words is "two hundred twenty-one billion, two hundred twenty-two million, two hundred twelve thousand, one hundred twenty".