1221220112200 has 72 divisors (see below), whose sum is σ = 3120923939490. Its totient is φ = 444080032000.

The previous prime is 1221220112131. The next prime is 1221220112201. The reversal of 1221220112200 is 22110221221.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 878220133956 + 342999978244 = 937134^2 + 585662^2 .

It is not an unprimeable number, because it can be changed into a prime (1221220112201) 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 17 ways as a sum of consecutive naturals, for example, 25207621 + ... + 25256020.

Almost surely, 2^{1221220112200} is an apocalyptic number.

1221220112200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221220112200 is an abundant number, since it is smaller than the sum of its proper divisors (1899703827290).

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

1221220112200 is a wasteful number, since it uses less digits than its factorization.

1221220112200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 50463679 (or 50463659 counting only the distinct ones).

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 1221220112200 its reverse (22110221221), we get a palindrome (1243330333421).

The spelling of 1221220112200 in words is "one trillion, two hundred twenty-one billion, two hundred twenty million, one hundred twelve thousand, two hundred".