1200021211121 has 4 divisors (see below), whose sum is σ = 1200035312244. Its totient is φ = 1200007110000.

The previous prime is 1200021211093. The next prime is 1200021211139. The reversal of 1200021211121 is 1211121200021.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1135639760896 + 64381450225 = 1065664^2 + 253735^2 .

It is a cyclic number.

It is not a de Polignac number, because 1200021211121 - 2²² = 1200017016817 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1200021211096 and 1200021211105.

It is not an unprimeable number, because it can be changed into a prime (1200021211171) 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 3 ways as a sum of consecutive naturals, for example, 6922130 + ... + 7093371.

It is an arithmetic number, because the mean of its divisors is an integer number (300008828061).

Almost surely, 2^{1200021211121} is an apocalyptic number.

It is an amenable number.

1200021211121 is a deficient number, since it is larger than the sum of its proper divisors (14101123).

1200021211121 is an equidigital number, since it uses as much as digits as its factorization.

1200021211121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14101122.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1200021211121 its reverse (1211121200021), we get a palindrome (2411142411142).

The spelling of 1200021211121 in words is "one trillion, two hundred billion, twenty-one million, two hundred eleven thousand, one hundred twenty-one".