2121200021100 has 144 divisors (see below), whose sum is σ = 6328333460736. Its totient is φ = 548172000000.

The previous prime is 2121200021089. The next prime is 2121200021147. The reversal of 2121200021100 is 11200021212.

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2405425 + ... + 3166775.

It is an arithmetic number, because the mean of its divisors is an integer number (43946760144).

Almost surely, 2^{2121200021100} is an apocalyptic number.

2121200021100 is a gapful number since it is divisible by the number (20) 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 2121200021100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3164166730368).

2121200021100 is an abundant number, since it is smaller than the sum of its proper divisors (4207133439636).

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

2121200021100 is a wasteful number, since it uses less digits than its factorization.

2121200021100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 761656 (or 761649 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 2121200021100 its reverse (11200021212), we get a palindrome (2132400042312).

The spelling of 2121200021100 in words is "two trillion, one hundred twenty-one billion, two hundred million, twenty-one thousand, one hundred".