1211100221100 has 576 divisors, whose sum is σ = 4604305305600. Its totient is φ = 238121856000.

The previous prime is 1211100221083. The next prime is 1211100221113. The reversal of 1211100221100 is 11220011121.

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

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 191 ways as a sum of consecutive naturals, for example, 627187135 + ... + 627189065.

It is an arithmetic number, because the mean of its divisors is an integer number (7993585600).

Almost surely, 2^{1211100221100} is an apocalyptic number.

1211100221100 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 1211100221100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2302152652800).

1211100221100 is an abundant number, since it is smaller than the sum of its proper divisors (3393205084500).

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

1211100221100 is a wasteful number, since it uses less digits than its factorization.

1211100221100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3414 (or 3407 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 1211100221100 its reverse (11220011121), we get a palindrome (1222320232221).

The spelling of 1211100221100 in words is "one trillion, two hundred eleven billion, one hundred million, two hundred twenty-one thousand, one hundred".