221212210011220 has 24 divisors (see below), whose sum is σ = 464546127138408. Its totient is φ = 88484791411200.

The previous prime is 221212210011209. The next prime is 221212210011227. The reversal of 221212210011220 is 22110012212122.

It can be written as a sum of positive squares in 4 ways, for example, as 7890177630916 + 213322032380304 = 2808946^2 + 14605548^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221212210011227) 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 7 ways as a sum of consecutive naturals, for example, 15760080 + ... + 26283160.

It is an arithmetic number, because the mean of its divisors is an integer number (19356088630767).

Almost surely, 2^{221212210011220} is an apocalyptic number.

221212210011220 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221212210011220 is an abundant number, since it is smaller than the sum of its proper divisors (243333917127188).

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

221212210011220 is a wasteful number, since it uses less digits than its factorization.

221212210011220 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11574171 (or 11574169 counting only the distinct ones).

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 221212210011220 its reverse (22110012212122), we get a palindrome (243322222223342).

The spelling of 221212210011220 in words is "two hundred twenty-one trillion, two hundred twelve billion, two hundred ten million, eleven thousand, two hundred twenty".