221212100222220 has 384 divisors, whose sum is σ = 690088373452800. Its totient is φ = 52714287628288.

The previous prime is 221212100222209. The next prime is 221212100222249. The reversal of 221212100222220 is 22222001212122.

It is an unprimeable number.

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 127 ways as a sum of consecutive naturals, for example, 225643861 + ... + 226622099.

It is an arithmetic number, because the mean of its divisors is an integer number (1797105139200).

Almost surely, 2^{221212100222220} is an apocalyptic number.

221212100222220 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 221212100222220, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (345044186726400).

221212100222220 is an abundant number, since it is smaller than the sum of its proper divisors (468876273230580).

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

221212100222220 is a wasteful number, since it uses less digits than its factorization.

221212100222220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 978457 (or 978455 counting only the distinct ones).

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

Adding to 221212100222220 its reverse (22222001212122), we get a palindrome (243434101434342).

The spelling of 221212100222220 in words is "two hundred twenty-one trillion, two hundred twelve billion, one hundred million, two hundred twenty-two thousand, two hundred twenty".