1211100221200 has 120 divisors (see below), whose sum is σ = 2941374407400. Its totient is φ = 479186534400.

The previous prime is 1211100221167. The next prime is 1211100221333. The reversal of 1211100221200 is 21220011121.

It can be written as a sum of positive squares in 12 ways, for example, as 310400522496 + 900699698704 = 557136^2 + 949052^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15359476 + ... + 15438124.

It is an arithmetic number, because the mean of its divisors is an integer number (24511453395).

Almost surely, 2^{1211100221200} is an apocalyptic number.

1211100221200 is a gapful number since it is divisible by the number (10) 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 1211100221200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1470687203700).

1211100221200 is an abundant number, since it is smaller than the sum of its proper divisors (1730274186200).

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

1211100221200 is a wasteful number, since it uses less digits than its factorization.

1211100221200 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 79085 (or 79074 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1211100221200 its reverse (21220011121), we get a palindrome (1232320232321).

The spelling of 1211100221200 in words is "one trillion, two hundred eleven billion, one hundred million, two hundred twenty-one thousand, two hundred".