2121021121121 has 40 divisors (see below), whose sum is σ = 2582362567080. Its totient is φ = 1739787495936.

The previous prime is 2121021121103. The next prime is 2121021121129. The reversal of 2121021121121 is 1211211201212.

It can be written as a sum of positive squares in 4 ways, for example, as 17360961121 + 2103660160000 = 131761^2 + 1450400^2 .

It is a de Polignac number, because none of the positive numbers 2^k-2121021121121 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2121021121121.

It is not an unprimeable number, because it can be changed into a prime (2121021121129) by changing a digit.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 7733291 + ... + 8002863.

It is an arithmetic number, because the mean of its divisors is an integer number (64559064177).

Almost surely, 2^{2121021121121} is an apocalyptic number.

It is an amenable number.

2121021121121 is a deficient number, since it is larger than the sum of its proper divisors (461341445959).

2121021121121 is an equidigital number, since it uses as much as digits as its factorization.

2121021121121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 269743 (or 269722 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 17.

Adding to 2121021121121 its reverse (1211211201212), we get a palindrome (3332232322333).

The spelling of 2121021121121 in words is "two trillion, one hundred twenty-one billion, twenty-one million, one hundred twenty-one thousand, one hundred twenty-one".