1211220112100 has 72 divisors (see below), whose sum is σ = 2634327095400. Its totient is φ = 483386849280.

The previous prime is 1211220112097. The next prime is 1211220112121. The reversal of 1211220112100 is 12110221121.

It can be written as a sum of positive squares in 12 ways, for example, as 300661402276 + 910558709824 = 548326^2 + 954232^2 .

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, 121737926 + ... + 121747874.

It is an arithmetic number, because the mean of its divisors is an integer number (36587876325).

Almost surely, 2^{1211220112100} is an apocalyptic number.

1211220112100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211220112100 is an abundant number, since it is smaller than the sum of its proper divisors (1423106983300).

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

1211220112100 is a wasteful number, since it uses less digits than its factorization.

1211220112100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12609 (or 12602 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1211220112100 its reverse (12110221121), we get a palindrome (1223330333221).

The spelling of 1211220112100 in words is "one trillion, two hundred eleven billion, two hundred twenty million, one hundred twelve thousand, one hundred".