1211111111100 has 72 divisors (see below), whose sum is σ = 3822707081088. Its totient is φ = 293602692800.

The previous prime is 1211111111087. The next prime is 1211111111143. The reversal of 1211111111100 is 11111111121.

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

It is a congruent number.

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, 183498384 + ... + 183504983.

It is an arithmetic number, because the mean of its divisors is an integer number (53093153904).

Almost surely, 2^{1211111111100} is an apocalyptic number.

1211111111100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1211111111100 is an abundant number, since it is smaller than the sum of its proper divisors (2611595969988).

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

1211111111100 is a wasteful number, since it uses less digits than its factorization.

1211111111100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 367003395 (or 367003388 counting only the distinct ones).

The product of its (nonzero) digits is 2, while the sum is 12.

Adding to 1211111111100 its reverse (11111111121), we get a palindrome (1222222222221).

The spelling of 1211111111100 in words is "one trillion, two hundred eleven billion, one hundred eleven million, one hundred eleven thousand, one hundred".