1211000111100 has 216 divisors, whose sum is σ = 4164928552512. Its totient is φ = 292467801600.

The previous prime is 1211000111093. The next prime is 1211000111171. The reversal of 1211000111100 is 11110001121.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 356356 + ... + 1596555.

It is an arithmetic number, because the mean of its divisors is an integer number (19282076632).

Almost surely, 2^{1211000111100} is an apocalyptic number.

1211000111100 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 1211000111100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2082464276256).

1211000111100 is an abundant number, since it is smaller than the sum of its proper divisors (2953928441412).

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

1211000111100 is a wasteful number, since it uses less digits than its factorization.

1211000111100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1952997 (or 1952987 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 9.

Adding to 1211000111100 its reverse (11110001121), we get a palindrome (1222110112221).

The spelling of 1211000111100 in words is "one trillion, two hundred eleven billion, one hundred eleven thousand, one hundred".