1211111100100 has 36 divisors (see below), whose sum is σ = 2867030279568. Its totient is φ = 440404036000.

The previous prime is 1211111100049. The next prime is 1211111100109. The reversal of 1211111100100 is 10011111121.

It is a Harshad number since it is a multiple of its sum of digits (10).

It is not an unprimeable number, because it can be changed into a prime (1211111100109) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 550503946 + ... + 550506145.

It is an arithmetic number, because the mean of its divisors is an integer number (79639729988).

Almost surely, 2^{1211111100100} is an apocalyptic number.

1211111100100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211111100100 is an abundant number, since it is smaller than the sum of its proper divisors (1655919179468).

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

1211111100100 is a wasteful number, since it uses less digits than its factorization.

1211111100100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1101010116 (or 1101010109 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 10.

Adding to 1211111100100 its reverse (10011111121), we get a palindrome (1221122211221).

The spelling of 1211111100100 in words is "one trillion, two hundred eleven billion, one hundred eleven million, one hundred thousand, one hundred".