200021020021 has 4 divisors (see below), whose sum is σ = 200022195712. Its totient is φ = 200019844332.

The previous prime is 200021020009. The next prime is 200021020049. The reversal of 200021020021 is 120020120002.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 120020120002 = 2 ⋅60010060001.

It is a cyclic number.

It is not a de Polignac number, because 200021020021 - 2⁹ = 200021019509 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (200021020051) 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, 278325 + ... + 691018.

It is an arithmetic number, because the mean of its divisors is an integer number (50005548928).

Almost surely, 2^200021020021 is an apocalyptic number.

It is an amenable number.

200021020021 is a deficient number, since it is larger than the sum of its proper divisors (1175691).

200021020021 is an equidigital number, since it uses as much as digits as its factorization.

200021020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1175690.

The product of its (nonzero) digits is 16, while the sum is 10.

Adding to 200021020021 its reverse (120020120002), we get a palindrome (320041140023).

The spelling of 200021020021 in words is "two hundred billion, twenty-one million, twenty thousand, twenty-one".