1221100012200 has 96 divisors (see below), whose sum is σ = 3785966789760. Its totient is φ = 325578777600.

The previous prime is 1221100012193. The next prime is 1221100012201. The reversal of 1221100012200 is 22100011221.

It is a Harshad number since it is a multiple of its sum of digits (12).

It is not an unprimeable number, because it can be changed into a prime (1221100012201) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 4030417 + ... + 4322783.

It is an arithmetic number, because the mean of its divisors is an integer number (39437154060).

Almost surely, 2^{1221100012200} is an apocalyptic number.

1221100012200 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1221100012200 is an abundant number, since it is smaller than the sum of its proper divisors (2564866777560).

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

1221100012200 is a wasteful number, since it uses less digits than its factorization.

1221100012200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 299347 (or 299338 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 1221100012200 its reverse (22100011221), we get a palindrome (1243200023421).

The spelling of 1221100012200 in words is "one trillion, two hundred twenty-one billion, one hundred million, twelve thousand, two hundred".