2120220121021 has 4 divisors (see below), whose sum is σ = 2144042819100. Its totient is φ = 2096397422944.

The previous prime is 2120220121013. The next prime is 2120220121037. The reversal of 2120220121021 is 1201210220212.

It is a happy number.

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 1405028544921 + 715191576100 = 1185339^2 + 845690^2 .

It is a cyclic number.

It is not a de Polignac number, because 2120220121021 - 2³ = 2120220121013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2120220120986 and 2120220121004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2120220122021) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11911348906 + ... + 11911349083.

It is an arithmetic number, because the mean of its divisors is an integer number (536010704775).

Almost surely, 2^{2120220121021} is an apocalyptic number.

It is an amenable number.

2120220121021 is a deficient number, since it is larger than the sum of its proper divisors (23822698079).

2120220121021 is an equidigital number, since it uses as much as digits as its factorization.

2120220121021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23822698078.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 2120220121021 its reverse (1201210220212), we get a palindrome (3321430341233).

The spelling of 2120220121021 in words is "two trillion, one hundred twenty billion, two hundred twenty million, one hundred twenty-one thousand, twenty-one".