2121210020 has 48 divisors (see below), whose sum is σ = 4724416368. Its totient is φ = 797245440.

The previous prime is 2121210019. The next prime is 2121210059. The reversal of 2121210020 is 200121212.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 523768996 + 1597441024 = 22886^2 + 39968^2 .

It is a super-3 number, since 3×2121210020³ (a number of 29 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 2121209983 and 2121210010.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 213074 + ... + 222806.

It is an arithmetic number, because the mean of its divisors is an integer number (98425341).

Almost surely, 2^2121210020 is an apocalyptic number.

2121210020 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 2121210020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2362208184).

2121210020 is an abundant number, since it is smaller than the sum of its proper divisors (2603206348).

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

2121210020 is a wasteful number, since it uses less digits than its factorization.

2121210020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10400 (or 10398 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 2121210020 is about 46056.5958359929. The cubic root of 2121210020 is about 1284.8760184600.

Adding to 2121210020 its reverse (200121212), we get a palindrome (2321331232).

The spelling of 2121210020 in words is "two billion, one hundred twenty-one million, two hundred ten thousand, twenty".