200021012021 has 4 divisors (see below), whose sum is σ = 200021909100. Its totient is φ = 200020114944.

The previous prime is 200021012017. The next prime is 200021012047. The reversal of 200021012021 is 120210120002.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 75852871396 + 124168140625 = 275414^2 + 352375^2 .

It is a cyclic number.

It is not a de Polignac number, because 200021012021 - 2² = 200021012017 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 200021011993 and 200021012011.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (200021012621) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 173045 + ... + 655733.

It is an arithmetic number, because the mean of its divisors is an integer number (50005477275).

Almost surely, 2^200021012021 is an apocalyptic number.

It is an amenable number.

200021012021 is a deficient number, since it is larger than the sum of its proper divisors (897079).

200021012021 is an equidigital number, since it uses as much as digits as its factorization.

200021012021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 897078.

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

Adding to 200021012021 its reverse (120210120002), we get a palindrome (320231132023).

The spelling of 200021012021 in words is "two hundred billion, twenty-one million, twelve thousand, twenty-one".