1200021111100 has 72 divisors (see below), whose sum is σ = 3045262951808. Its totient is φ = 401867524800.

The previous prime is 1200021111073. The next prime is 1200021111109. The reversal of 1200021111100 is 11111200021.

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1200021111109) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19903806 + ... + 19964005.

Almost surely, 2^{1200021111100} is an apocalyptic number.

1200021111100 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1200021111100 is an abundant number, since it is smaller than the sum of its proper divisors (1845241840708).

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

1200021111100 is a wasteful number, since it uses less digits than its factorization.

1200021111100 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39867875 (or 39867868 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 10.

Adding to 1200021111100 its reverse (11111200021), we get a palindrome (1211132311121).

The spelling of 1200021111100 in words is "one trillion, two hundred billion, twenty-one million, one hundred eleven thousand, one hundred".