1211200121100 has 144 divisors (see below), whose sum is σ = 3539585952000. Its totient is φ = 319748440320.

The previous prime is 1211200121071. The next prime is 1211200121123. The reversal of 1211200121100 is 11210021121.

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, 49710721 + ... + 49735079.

It is an arithmetic number, because the mean of its divisors is an integer number (24580458000).

Almost surely, 2^{1211200121100} is an apocalyptic number.

1211200121100 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 1211200121100, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1769792976000).

1211200121100 is an abundant number, since it is smaller than the sum of its proper divisors (2328385830900).

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

1211200121100 is a wasteful number, since it uses less digits than its factorization.

1211200121100 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26032 (or 26025 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 1211200121100 its reverse (11210021121), we get a palindrome (1222410142221).

The spelling of 1211200121100 in words is "one trillion, two hundred eleven billion, two hundred million, one hundred twenty-one thousand, one hundred".